1.
Express as a single number: 3.8 x 104 – 9.7 x 10
Correct Answer
A. 37903
2.
If two numbers are added together, what it is called?
Correct Answer
A. Sum
Explanation
In mathematics, when you combine or add two or more numbers together, the result is called the "sum." The term "sum" refers to the total obtained by adding numbers. Here's a simple example:
If you have the numbers 3, 5, and 7, and you add them together:
3+5+7=15
Here, 15 is the sum of the numbers 3, 5, and 7. The process of adding these numbers is called addition, and the result is the sum.
So, in general terms, when you add or combine numbers using the "+" symbol, the outcome is referred to as the sum.
3.
The reciprocal of x2 is ___.
Correct Answer
A. X-2
Explanation
The reciprocal of x^2 is x^-2 because when we take the reciprocal of a number, we flip it upside down. In this case, we are taking the reciprocal of x^2, so we flip it to get 1/x^2. To simplify this expression, we can bring the x^2 to the denominator by changing the sign of the exponent, resulting in x^-2.
4.
Mr. Ojo made a profit of 32% on an article he bought for N3,200.00. How much did he sell the article?
Correct Answer
D. N4,224.00
5.
Number 1, 2, 3, 4, 5, 6 ___ are called.
Correct Answer
C. Natural number
Explanation
Natural numbers are positive integers starting from 1 (1, 2, 3, …). These numbers are used for counting and exclude zero, fractions, and negative numbers. Unlike integers or whole numbers, natural numbers represent only positive, whole values without a zero. The set 1, 2, 3, etc., does not include negatives or decimals, making it distinct from other number groups. Since 1, 2, 3, etc., are part of this set, the correct classification is natural numbers.
6.
If 2x0 and 4x0 are supplementary angles. What is the value of x?
Correct Answer
C. 30
Explanation
If two angles are supplementary, it means that the sum of their measures is 180 degrees.
In this case, you have two angles: 2x and 4x.
So, you can write the equation:
2x + 4x = 180
Combine like terms:
6x = 180
Now, divide both sides by 6 to solve for x:
6x/6 = 180/6
x = 30
So, the value of x is 30.
7.
Find the reciprocal of 2.5 ___.
Correct Answer
D. 0.4
Explanation
The reciprocal of 2.5 is found by dividing 1 by 2.5: 1 ÷ 2.5 = 0.4. To simplify, write 2.5 as a fraction: 1 ÷ (5/2). Multiplying by the reciprocal: 1 × (2/5) = 2/5 = 0.4. Converting the decimal 2.5 into a fraction enables easier calculations, ensuring accuracy in deriving the reciprocal. The result is 0.4.
8.
If 15 men dig a trench for 10 days, how many men will be required to dig the trench in 2 days?
Correct Answer
B. 75 men
9.
Express 675 000 000 in a standard form.
Correct Answer
A. 6.75 x 108
Explanation
The correct answer is A. 6.75 x 10^8. This is because in standard form, a number is expressed as a decimal between 1 and 10 multiplied by a power of 10. So, 675,000,000 can be written as 6.75 multiplied by 100,000,000, which can be further simplified to 6.75 x 10^8.
10.
A trader buys a gallon of palm oil for N1,500.00 and sells it at a profit of 10%. Calculate the selling price.
Correct Answer
B. N1,650.00
Explanation
Selling price = cost price + profit. Profit = cost price × profit %. Here, profit = 1500 × 10/100 = 150. Add this to the cost price: 1500 + 150 = 1650. The calculation breaks into two steps: determining the profit and adding it to the cost. Thus, the selling price is 1650.
11.
Find the mean score of these scores: 2, 3, 0, 8, 7, 5, 9, 6
Correct Answer
C. 5.00
Explanation
The mean score is calculated by adding all the scores together and then dividing the sum by the total number of scores. In this case, the sum of the scores is 2+3+0+8+7+5+9+6=40. Since there are 8 scores, the mean score is 40/8=5.00. Therefore, the correct answer is C. 5.00.
12.
Find the HCF of 36 and 60.
Correct Answer
A. 12
Explanation
The HCF (Highest Common Factor) of two numbers is the largest number that divides both of them without leaving a remainder. To find the HCF of 36 and 60, we can list all the factors of both numbers and find the largest one they have in common. The factors of 36 are 1, 2, 3, 4, 6, 9, 12, 18, and 36. The factors of 60 are 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, and 60. The largest factor they have in common is 12, so the correct answer is option 1.
13.
How many lines of symmetry have a square?
Correct Answer
B. 4
Explanation
A square has 4 lines of symmetry. Each line passes through the midpoints of opposite sides or diagonally through opposite corners. These lines divide the square into two equal halves. Thus, the number of lines of symmetry for a square is 4.
14.
If a rectangle has a length of 10 cm and a width of 5 cm, what is the perimeter of the rectangle?
Correct Answer
B. 30 cm
15.
Simplify (-4 X -2 X -3)/(-2 X 6)
Correct Answer
D. 2
Explanation
First, calculate the numerator: (-4) × (-2) × (-3) = -24. Then, calculate the denominator: (-2) × 6 = -12. Divide: (-24) ÷ (-12) = -2. The negative signs cancel out during division. Thus, the simplified value is -2.
16.
Simplify ab (a – b)
Correct Answer
A. A2b – ab2
Explanation
To simplify the expression, we use the distributive property:
ab (a – b) = ab * a – ab * b
This simplifies to a²b – ab²
17.
Express 18 as a product of its prime factors.
Correct Answer
B. 2x3x3=21x32
Explanation
To find the prime factors of 18, divide it by the smallest prime number, 2: 18 ÷ 2 = 9. Next, divide 9 by 3: 9 ÷ 3 = 3. Divide again by 3: 3 ÷ 3 = 1. The prime factorization is 2 × 3 × 3 or 2¹ × 3².
18.
Factorize 81 + 18a + a.
Correct Answer
B. (a+9) (a+9)
Explanation
To factorize the given expression, 81 + 18a + a^2, we need to find two binomials that, when multiplied, produce the given expression.
Let's consider the given options:
(a+9)(a-9): When multiplied, this would result in a^2 - 81, which is different from the given expression.
(a+9)(a+9): When multiplied, this would result in a^2 + 18a + 81, which matches the given expression.
(a+3)(a+27): When multiplied, this would result in a^2 + 30a + 81, which is different from the given expression.
(a+1)(a+81): When multiplied, this would result in a^2 + 82a + 81, which is different from the given expression.
Therefore, the correct factorization of 81 + 18a + a^2 is (a+9)(a+9).
19.
The difference between the median and the mode of the following set of numbers: 7, 4, 9, 5, 6, 7, 8, 7, 4,6, 5 is ___.
Correct Answer
B. -1
Explanation
To find the median, we first need to arrange the numbers in ascending order: 4, 4, 5, 5, 6, 6, 7, 7, 7, 8, 9. There are 11 numbers in this set, which is an odd number, so the median is the middle value, which is 6. The mode is the number that appears most frequently in the set. In this case, the number 7 appears three times, which is more frequent than any other number in the set. Now, let's calculate the difference between the median and the mode:
Median (6) - Mode (7) = 6 - 7 = -1
So, the difference between the median and the mode of the given set of numbers is -1, which corresponds to option B.
20.
Numbers that cannot be expressed as fractions are called ___
Correct Answer
C. Irrational numbers
Explanation
Irrational numbers are numbers that cannot be expressed as a fraction of two integers. They have decimal representations that neither terminate nor repeat. Some famous examples of irrational numbers include pi (π) and the square root of 2.
21.
Express 0.000 000 000347 in standard form.
Correct Answer
D. 3.47 x 10-10
22.
Find the Simple Interest on ₦500.00 for 2 years at 4%.
Correct Answer
B. ₦40.00
Explanation
The correct answer is B. ₦40.00. The formula to calculate simple interest is Principal x Rate x Time. In this case, the principal is ₦500.00, the rate is 4%, and the time is 2 years. Plugging these values into the formula, we get ₦500.00 x 0.04 x 2 = ₦40.00. Therefore, the simple interest on ₦500.00 for 2 years at 4% is ₦40.00.
23.
Solve the equation 2 ½ = 1/y
Correct Answer
C. 2/5
Explanation
The equation 2 ½ = 1/y can be solved by multiplying both sides of the equation by y. This eliminates the fraction on the left side of the equation. The equation becomes 2y = 1. To isolate y, divide both sides of the equation by 2. This gives y = 1/2. However, this is not one of the answer options provided. Therefore, the correct answer is not available.
24.
If the sum of three consecutive even integers is 114, what is the largest of these integers?
Correct Answer
C. 40
Explanation
Let's call the first even integer x. Since they are consecutive even integers, the second integer would be x+2 and the third integer would be x+4. The sum of these three integers is 114. So the equation would be:
x + (x+2) + (x+4) = 114 3x + 6 = 114 3x = 108 x = 36 (dividing both sides by 3) The largest of these integers would be x+4 which is equal to x+4=36+4=40. Therefore the largest integer is 40.
25.
Simplify X6÷X3
Correct Answer
C. X3
Explanation
The expression X6/X3 can be simplified by dividing the exponents. When dividing variables with the same base, you subtract the exponents. Therefore, X6/X3 is equal to X6-3, which simplifies to X3.
26.
Find the highest common factor of 325, 350, and 375
Correct Answer
D. 25
Explanation
The highest common factor (HCF) of three numbers can be found by finding the factors of each number and then identifying the largest factor that is common to all three numbers. The factors of 325 are 1, 5, 13, 25, 65, and 325. The factors of 350 are 1, 2, 5, 7, 10, 14, 25, 35, 50, 70, 175, and 350. The factors of 375 are 1, 3, 5, 15, 25, 75, and 375. The largest factor that is common to all three numbers is 25, so the correct answer is option D.
27.
Express 6561 in index form.
Correct Answer
B. 94
Explanation
To express 6561 in index form, we need to find a number that, when raised to a power, results in 6561. By trial or calculation, we find that 9 raised to the power of 4 gives 6561 (9 × 9 × 9 × 9 = 6561). Therefore, the correct index form of 6561 is 9⁴. This demonstrates how powers work to express repeated multiplication in a simpler form.
28.
What is the value of 962?
Correct Answer
C. 9216
Explanation
The expression 9² represents 9 multiplied by itself. So, 9 × 9 = 81. This is the correct value of 9². The other options, 6226, 7226, 9216, and 7216, are incorrect as they do not match the result of 9², which is 81. Therefore, the correct answer is 81.
29.
Simplify ( x/3)2
Correct Answer
B. X2/9
Explanation
To simplify (x/3)², you square both the numerator and denominator. The numerator, x, squared is x², and the denominator, 3, squared is 9. Therefore, the simplified expression becomes x²/9. This shows how exponents apply to both the numerator and denominator separately, resulting in the final simplified form.
30.
If a = 2, put (>, <, , or =) in the box for the inequality below: -23___ -45
Correct Answer
A. >
Explanation
When a = 2, the inequality is -23 compared to -45. Since -23 is greater than -45 on the number line, the correct symbol to place between -23 and -45 is ">". This means that -23 is indeed greater than -45. Therefore, the correct symbol is ">", indicating that -23 is larger than
31.
The number of pupils in a school is 875. If 350 are girls, what percentage of the pupils are boys?
Correct Answer
B. 60%
Explanation
The correct answer is B. 60%. Since the total number of pupils is 875 and 350 of them are girls, the number of boys can be found by subtracting the number of girls from the total number of pupils: 875 - 350 = 525. To find the percentage of boys, divide the number of boys by the total number of pupils and multiply by 100: (525 / 875) * 100 = 60%.
32.
The lowest common denominator of 1/4, 2/3, 4/5, 5/6 and 5/10 and is ___.
Correct Answer
D. 60
Explanation
The lowest common denominator of a set of fractions is the smallest number that each denominator can divide into evenly. In this case, the denominators are 4, 3, 5, 6, and 10. The lowest common denominator for these numbers is 60, as it is the smallest number that all of these denominators can divide into evenly.
33.
These numbers are square numbers except.
Correct Answer
B. 224
Explanation
The given numbers are 324, 224, 196, and 169. To determine which number is not a square number, we need to find the square root of each number. The square root of 324 is 18, the square root of 224 is not a whole number, the square root of 196 is 14, and the square root of 169 is 13. Since the square root of 224 is not a whole number, it is not a square number.
34.
What is the sum of the first 20 odd numbers?
Correct Answer
B. 400
Explanation
The first 20 odd numbers form an arithmetic progression with the first term being 1, the common difference being 2, and the number of terms being 20. The sum 'S' of an arithmetic progression is given by S = n/2 [2a + (n-1)d], where 'n' is the number of terms, 'a' is the first term, and 'd' is the common difference. 1 Substituting these values into the formula gives S = 20/2 [2(1) + (20-1)2] = 10 (2 + 38) = 10 (40) = 400.
35.
The sum of x in minutes and y seconds expressed in minutes is ___.
Correct Answer
D. X + y/60
Explanation
The correct answer is D. x + y/60. This is because when converting seconds to minutes, we divide the number of seconds by 60. So, to express the sum of x minutes and y seconds in minutes, we add x to the quotient of y divided by 60.
36.
If N9 600 was shared among three boys Ola, Tope, and Jide in the ratio 3: 4: 5, respectively, what is Jide’s share?
Correct Answer
B. N4,000
Explanation
Jide's share can be found by dividing the total amount shared (N9,600) in the ratio of 3:4:5. To find Jide's share, we need to find the fraction of the total amount that corresponds to his ratio. The fraction for Jide is 5 out of the total ratio of 3+4+5, which is 12. Therefore, Jide's share is (5/12) * N9,600 = N4,000.
37.
Complete the following sentence correctly. Vertically opposite angles ___.
Correct Answer
A. Are equal
Explanation
Vertically opposite angles are equal. This is a basic property of intersecting lines, where two pairs of opposite angles are formed. These angles have the same measure and are considered congruent.
38.
John thinks of a number. 18 is subtracted from the number, the result gives – 2. What is the number?
Correct Answer
B. 16
39.
Find the probability of choosing a vowel from ‘KETU–LAGOS’.
Correct Answer
D. 4/9
Explanation
The given question asks for the probability of choosing a vowel from the given word "KETU-LAGOS". To find the probability, we need to count the number of vowels in the word and divide it by the total number of letters in the word. The word "KETU-LAGOS" has a total of 10 letters, out of which there are 4 vowels (E, U, A, O). Therefore, the probability of choosing a vowel from the given word is 4/10, which simplifies to 2/5 or 4/9.
40.
Increase 12 by 30%.
Correct Answer
C. 15.6
Explanation
To increase a number by a certain percentage, you can multiply the number by 1 plus the percentage as a decimal. In this case, to increase 12 by 30%, you would calculate 12 * (1 + 0.30) = 12 * 1.30 = 15.6. Therefore, the correct answer is option C, 15.6.
41.
How many faces have a cylinder?
Correct Answer
B. 2
Explanation
A cylinder has two circular faces, one at the top and one at the bottom. These are the flat surfaces of the cylinder. The curved surface that wraps around the sides is not considered a face in the context of counting faces.
42.
Factorize x2 – 1.
Correct Answer
A. (x-1) (x+1)
Explanation
The expression x² - 1 is a difference of squares, and it can be factored using the formula a² - b² = (a - b)(a + b). In this case, x² - 1 can be factored as (x - 1)(x + 1), which is the correct factorization. The other options are incorrect because they don't follow the difference of squares rule. Thus, the factorization of x² - 1 is (x - 1)(x + 1).
43.
The point where the x-axis crosses the y-axis in a graph is called ___
Correct Answer
C. Origin
Explanation
The point where the x-axis crosses the y-axis in a graph is called the origin. In a coordinate plane, the origin is represented by the coordinates (0, 0), where both x and y are zero. This is the point of intersection of the x-axis and y-axis. The other options are incorrect, as "Cartesian" refers to the coordinate system, "intersection" is a general term, and "ordered pairs" refer to coordinates.
44.
The product of 0.017 and 100 is ____________
Correct Answer
D. 1.7
Explanation
To find the product of 0.017 and 100, you multiply the numbers. When you multiply 0.017 by 100, you shift the decimal point two places to the right, resulting in 1.7. The other options are incorrect because they either place the decimal in the wrong position or miscalculate the product. Therefore, the correct result of multiplying 0.017 by 100 is 1.7.
45.
What is the correct name for one thousand billion?
Correct Answer
D. One trillion
Explanation
One thousand billion is equal to one trillion. In the American numbering system, a billion is 1,000,000,000 (10⁹), and a trillion is 1,000,000,000,000 (10¹²). Therefore, one thousand billion equals one trillion. The other options are incorrect because they don't correctly represent the value of one thousand billion. Thus, the correct name for one thousand billion is "one trillion."
46.
Factorize 24pz – 8pr.
Correct Answer
A. 8p (3z –r)
Explanation
The given expression can be factorized as 8p(3z - r). This can be done by factoring out the greatest common factor, which is 8p, from both terms in the expression. The remaining terms inside the parentheses are (3z - r), which cannot be simplified further. Therefore, the correct factorization is 8p(3z - r).
47.
Express 1740m in km, leaving your answer in standard form.
Correct Answer
A. 1.74 x 10 0 km
Explanation
To convert meters to kilometers, divide by 1000 because there are 1000 meters in one kilometer.
1740 meters ÷ 1000 = 1.74 kilometers.
To express 1.74 kilometers in standard form, we write it as 1.74 x 10³, which represents 1.74 multiplied by 10 raised to the power of 3. This is the correct standard form. The other options are incorrect because they do not represent the correct power of 10 for converting 1740 meters to kilometers.
48.
The least number by which 112 must be multiplied to give a perfect square is __
Correct Answer
C. 7
Explanation
To find the least number by which 112 must be multiplied to give a perfect square, we need to find the prime factors of 112. The prime factorization of 112 is 2 * 2 * 2 * 2 * 7. In order for the number to be a perfect square, each prime factor must have an even exponent. The exponent of 2 is already even, but the exponent of 7 is 1, which is odd. Therefore, we need to multiply 112 by 7 to make the exponent of 7 even. Hence, the correct answer is option C.
49.
Express 20% as a decimal number.
Correct Answer
C. 0.2
Explanation
To express a percentage as a decimal number, you divide the percentage by 100. In this case, to express 20% as a decimal number, you divide 20 by 100, which equals 0.2. Therefore, the correct answer is option 3, 0.2.
50.
The LCM of 5ab2 and 3a2b is:
Correct Answer
D. 15a2b2
Explanation
The LCM (Least Common Multiple) of two numbers is the smallest number that is divisible by both numbers. In this case, the given numbers are 5ab2 and 3a2b. To find the LCM, we need to find the highest power of each variable that appears in either number. In this case, the highest power of 'a' is 2 and the highest power of 'b' is 2. Therefore, the LCM is 15a2b2, which is Option 4.