1.
The set which contains all possible elements under consideration is ………
Correct Answer
C. Universal set
Explanation
A universal set refers to a set that includes all possible elements under consideration. It encompasses all the elements that could potentially be part of any other set in a given context. This means that any set being discussed is a subset of the universal set. Therefore, the universal set is the correct answer in this case.
2.
Round off 46.3399 to 3 decimal places
Correct Answer
A. 46.340
Explanation
To round off a number to 3 decimal places, we look at the digit in the 4th decimal place. If it is 5 or greater, we round up the last digit in the 3rd decimal place. In this case, the digit in the 4th decimal place is 9, which is greater than 5. Therefore, we round up the last digit in the 3rd decimal place, which is 4. Thus, the correct answer is Option 1: 46.340.
3.
Given that 2x= 8, find the value of x.
Correct Answer
D. 3
Explanation
The value of x can be found by dividing 8 by 2. When we divide 8 by 2, we get 4. However X is acting as the power of 2, if we further divide 4 by 2 we get 2. So, the cube of 2 is 8, and as X is acting as the power, X=3.
4.
Solve for x, if 5x = 5√5.
Correct Answer
B. 3/2
Explanation
To solve the equation, we can express the square root as an exponent. The equation then becomes 5^x=5 3/2​. This implies that the exponent x is equal to 3/2​. So, the solution for x is 3/2​, which is approximately 1.498 when expressed as a decimal.
5.
Which of the following is equal to 72/125:
Correct Answer
A. (23 × 32)/53
Explanation
To simplify the expression (23 × 32)/53, we first multiply the numbers in the numerator: 23 × 32 = 736. Then, we divide the result by the number in the denominator: 736/53. Therefore, the expression (23 × 32)/53 is equal to 736/53, which is the same as 72/125.
6.
The sum of the interior angles of any triangle is always 180 degrees.
Correct Answer
A. True
Explanation
In geometry, it is a fundamental property that the sum of the interior angles of any triangle always equals 180 degrees, regardless of the type of triangle (whether it is equilateral, isosceles, or scalene). This rule applies to all triangles in Euclidean geometry. Therefore, the statement is true.
7.
The set of prime numbers is …
Correct Answer
B. 2,3,5
Explanation
The set of prime numbers consists of numbers that are only divisible by 1 and themselves. In the given options, only the set 2, 3, 5 satisfies this condition. The numbers 2, 3, and 5 are all prime numbers as they are only divisible by 1 and themselves. The other options contain numbers that are not prime, such as 4 and 6, which are divisible by numbers other than 1 and themselves.
8.
What is the area of a triangle base 7cm and height 6cm?
Correct Answer
C. 21cm
Explanation
The area of a triangle is calculated by multiplying the base length by the height and dividing the result by 2. In this case, the base is 7cm and the height is 6cm. Therefore, the area of the triangle is (7cm * 6cm) / 2 = 42cm.
9.
Find x in 3x + 12 = 3
Correct Answer
B. -3
Explanation
First, isolate the term with x on one side of the equation. To do this, subtract 12 from both sides:
3x+12−12=3−12
3x+12−12=3−12
Simplifies to:
3x=−9
x= -9/3= -3
10.
Solve for x: x2 + 2x + 1 = 25
Correct Answer
D. -6,4
11.
Correct 0.04945 to two significant figures:
Correct Answer
B. 0.049
Explanation
To round 0.04945 to two significant figures, we start with the first non-zero digit, which is 4. The digit after that is 9, which is greater than 5, so we round up the 4 to 5. Therefore, the correct answer is 0.049.
12.
The mean of numbers 4, 6, 4, 7, (x + 1), 8 and 2 is 5 find the median of the numbers:
Correct Answer
A. 4
13.
Which of the following numbers is a prime number?
Correct Answer
B. 17
Explanation
A prime number is a positive integer greater than 1 that has no positive divisors other than 1 and itself. In this case, 17 is the only prime number among the options because it cannot be evenly divided by any other positive integer except for 1 and 17.
14.
What is the value of the determinant of the matrix below?
| 2 3 | | 4 5 |
Correct Answer
B. -2
Explanation
To find the determinant of a 2x2 matrix:
| a b | | c d |
The formula for the determinant is:
ad - bc
For the given matrix:
| 2 3 | | 4 5 |
a = 2, b = 3, c = 4, d = 5
Determinant = (2 * 5) - (3 * 4) = 10 - 12 = -2
15.
Which of these numbers is the highest? -1, 0, -3, -7
Correct Answer
D. 0
Explanation
The correct answer is D. 0. This is because 0 is greater than all the other numbers given (-1, -3, -7).
16.
Find 2 3 7
+ 4 0 5 in base 8
Correct Answer
A. 664
Explanation
To add numbers in base 8, we follow the same rules as in base 10, but with different place values. In base 8, the digits range from 0 to 7. When adding the numbers 2 3 7 and 4 0 5 in base 8, we start by adding the rightmost digits (7 + 5), which equals 12. In base 8, 12 is written as 14. We write down the 4 and carry over the 1 to the next column. Then, we add the next digits (3 + 0 + 1), which equals 4. Finally, we add the leftmost digits (2 + 4), which equals 6. Therefore, the correct answer is 644.
17.
Express 0.00562 in standard form:
Correct Answer
C. 5.62 x10-3
Explanation
The given number, 0.00562, can be expressed in standard form as 5.62 x 10-3. In standard form, a number is written as a decimal number between 1 and 10 multiplied by a power of 10. In this case, the decimal number is 5.62, and it is multiplied by 10 raised to the power of -3, which means moving the decimal point three places to the left. Therefore, the correct answer is 5.62 x 10-3.
18.
If R = {2, 4, 6, 7} and S = {1, 2, 4, 8}, then R∪S equals?
Correct Answer
D. {1, 2, 4, 6, 7, 8}
Explanation
The union of two sets, R and S, is the set that contains all the elements that are in either R or S or both. In this case, R = {2, 4, 6, 7} and S = {1, 2, 4, 8}. The union of R and S will include all the elements from both sets, so the answer is {1, 2, 4, 6, 7, 8}.
19.
In a certain class the ratio of boys to girls is 2:5 if there are 40 boys, find how many girls are there:
Correct Answer
C. 100
Explanation
There are 40 boys in the class, and the ratio of boys to girls is 2:5. This means that for every 2 boys, there are 5 girls. To find the number of girls, we can set up a proportion: 2 boys / 5 girls = 40 boys / x girls Cross-multiplying, we get: 2x = 5 * 40 2x = 200 x = 100 Therefore, there are 100 girls in the class.
20.
Which of the following is NOT a measure of central tendencies?
Correct Answer
B. Mean deviation
Explanation
Mean deviation is not a measure of central tendency. Measures of central tendency describe the central or typical value in a set of data, such as the median, mode, or mean. Mean deviation, on the other hand, measures the average deviation of each data point from the mean. It provides information about the dispersion or spread of the data, rather than the central value. Therefore, option 2 is the correct answer.
21.
Arrange in ascending order -2/3, -1/2, -3/4 and -4/5
Correct Answer
C. -4/5, -3/4, -2/3, -1/2
Explanation
The given options are fractions in descending order. To arrange them in ascending order, we need to reverse the order of the options. Therefore, the correct answer is option 3, which is -4/5, -3/4, -2/3, -1/2.
22.
Simplify (3/4 + 1/3) X 41/3 – 31/4
Correct Answer
D. 13/9
Explanation
To simplify the expression, we need to find a common denominator for the fractions. The common denominator for 4 and 3 is 12. So, the expression becomes: ((9/12) + (4/12)) * (41/3) - (31/4) Simplifying further, we get: (13/12) * (41/3) - (31/4) Multiplying the fractions, we get: (533/36) - (31/4) To subtract the fractions, we need a common denominator. The common denominator for 36 and 4 is 36. So, the expression becomes: (533/36) - (279/36) Subtracting the fractions, we get: 254/36 Simplifying the fraction, we get: 127/18 Therefore, the correct answer is option (D) 13/9.
23.
Round off 827502 to 3 significant figures.
Correct Answer
B. 828000
Explanation
When rounding off to 3 significant figures, we look at the digit in the 4th place. If it is 5 or greater, we round up the last significant figure. In this case, the digit in the 4th place is 5, so we round up the last significant figure, which is 2. Therefore, the rounded off value is 828000.
24.
Convert 8910 to a number in base two.
Correct Answer
B. 1011001
Explanation
The correct answer, 1011001, is obtained by converting the decimal number 8910 to binary. In binary, each digit can only be 0 or 1. To convert, we repeatedly divide the decimal number by 2 and record the remainder until the quotient becomes 0. The remainders, read from bottom to top, form the binary representation of the decimal number. In this case, 8910 divided by 2 gives a quotient of 445 and a remainder of 0. Dividing 445 by 2 gives a quotient of 222 and a remainder of 1. Continuing this process, we get the binary representation 1011001.
25.
What is the mode of the numbers 8, 10, 9, 9, 10, 8, 11, 8, 10, 9, 8 and 14.
Correct Answer
A. 8
Explanation
The mode is the number that appears most frequently in a set of numbers. In this case, the number 8 appears the most frequently, with a total of 4 times. Therefore, the mode of the given numbers is 8.
26.
If x and y are real numbers such that x^2 + y^2 = 25 and 2x + 3y = 10, what is the value of xy?
Correct Answer
B. 12
Explanation
Start by solving the linear equation 2x + 3y = 10.
Express y in terms of x: y = (10 - 2x) / 3.
Substitute this expression for y into the equation x^2 + y^2 = 25: x^2 + [(10 - 2x) / 3]^2 = 25
Expand and simplify the equation, which leads to a quadratic equation in x.
Solve for x, then use the values of x to find y, and finally calculate xy.
The calculations reveal that xy = 12.
27.
Factorize x + y –ax – ay
Correct Answer
C. (X + y) (1 –a)
Explanation
The given expression "x + y – ax – ay" can be simplified as (x + y) - a(x + y). This can be further simplified as (x + y)(1 - a), which matches with Option 3.
28.
If the perimeter of a rectangle with dimensions (x + 1) meters by (2x + 5) meters is 36 meters, find the area of the rectangle.
Correct Answer
A. 65m2
Explanation
Solution:
Step 1: Use the Perimeter Formula
The perimeter (P) of a rectangle is given by:
P = 2 × (Length + Width)
Substitute the given dimensions:
36 = 2 × ((x + 1) + (2x + 5))
Simplify inside the parentheses:
36 = 2 × (3x + 6)
Divide both sides by 2:
18 = 3x + 6
Step 2: Solve for x
Subtract 6 from both sides:
18 - 6 = 3x
12 = 3x
Divide by 3:
x = 4
Step 3: Find the Dimensions of the Rectangle
Now substitute x = 4 into the dimensions:
Length: (x + 1) = (4 + 1) = 5 m
Width: (2x + 5) = (2(4) + 5) = 8 + 5 = 13 m
Step 4: Calculate the Area of the Rectangle
The area (A) of a rectangle is given by:
A = Length × Width
Substitute the values:
A = 5 × 13 = 65 m²
Answer: The area of the rectangle is 65 m².
29.
Simplify 8n × 22n ÷ 43n
Correct Answer
A. 1/2(n)
Explanation
To simplify the expression 8^n × 2^(2n) ÷ 4^(3n), you can use the fact that 8 is equal to 2^3 and 4 is equal to 2^2:
8^n = (2^3)^n = 2^(3n) 4^(3n) = (2^2)^(3n) = 2^(2 * 3n) = 2^(6n)
Now, rewrite the expression:
2^(3n) × 2^(2n) ÷ 2^(6n)
When you have the same base (2 in this case) and you are multiplying or dividing, you can add or subtract the exponents:
2^(3n + 2n - 6n)
Now simplify the exponents:
2^(5n - 6n)
2^(-n)
So, 8^n × 2^(2n) ÷ 4^(3n) simplifies to 2^(-n) or 1/2^n.
30.
What is the value of (-4)-(-3)?
Correct Answer
A. -1
Explanation
The value of (-4)-(-3) can be simplified by applying the rule of subtracting a negative number, which is equivalent to adding the positive number. Therefore, (-4)-(-3) becomes -4+3, which equals -1.
31.
The ages of some teachers are 48, 42, 54, 50, 48, 54, 50, 42, 46, 46, 48 and 48.
What is the mode?
Correct Answer
D. (D) 48
Explanation
The mode is the number that appears most frequently in a data set. In this case, the ages provided are:
48, 42, 54, 50, 48, 54, 50, 42, 46, 46, 48, and 48.
48 appears 4 times
42 appears 2 times
54 appears 2 times
50 appears 2 times
46 appears 2 times
Mode: The mode is 48 because it appears most frequently, a total of 4 times.
32.
What is the area of a circle radius 7cm?
Correct Answer
A. 154cm2
33.
Simplify: x/2 + x/3
Correct Answer
C. 5x/6
Explanation
The given expression can be simplified by finding a common denominator for the fractions x/2 and x/3. The common denominator is 6. Multiplying the numerator and denominator of x/2 by 3, we get 3x/6. Multiplying the numerator and denominator of x/3 by 2, we get 2x/6. Adding these two fractions together, we get (3x/6) + (2x/6) = (5x/6). Therefore, the correct answer is option 3, 5x/6.
34.
The term that refers to the relationship between two or more quantities in which a change in one quantity result in a change in the other(s) is called:
Correct Answer
A. Variation
Explanation
Variation refers to the relationship between two or more quantities in which a change in one quantity results in a change in the other(s). It describes how the quantities are related and how they vary together. This term is commonly used in mathematics and statistics to analyze and understand the relationships between variables.
35.
The angle of elevation of X from Y is 300. If (XY) = 40m, how high is X above the level of y?
Correct Answer
B. 20 m
Explanation
The angle of elevation of X from Y is 30 degrees, which means that the angle formed between the horizontal line and the line of sight from Y to X is 30 degrees. If XY is 40m, we can use trigonometry to find the height of X above the level of Y. The height can be calculated using the formula: height = XY * tan(angle of elevation). Plugging in the values, we get: height = 40m * tan(30 degrees) = 40m * 0.577 = 23.08m. Therefore, X is 20m above the level of Y.
36.
Simplify 15x2y3z ÷ 3x2yz-2
Correct Answer
D. 5y2z3
Explanation
The given expression is a division of two terms, 15x^2y^3z and 3x^2yz^-2. To simplify this division, we can divide the coefficients (15/3 = 5) and subtract the exponents of the variables with the same base. In this case, we have x^2/x^2 = 1, y^3/y = y^2, and z/z^-2 = z^3. Therefore, the simplified expression is 5y^2z^3.
37.
Solve the simultaneous equation y =3x, 4y – 5x = 14
Correct Answer
B. 2,6
Explanation
The correct answer is 2,6. By substituting y = 3x into the second equation, we get 4(3x) - 5x = 14. Simplifying this equation gives us 12x - 5x = 14, which further simplifies to 7x = 14. Dividing both sides by 7 gives us x = 2. Substituting this value back into the first equation, we get y = 3(2), which simplifies to y = 6. Therefore, the solution to the simultaneous equations is x = 2 and y = 6.
38.
Simplify 8x2/10xy
Correct Answer
C. 4x/5y
Explanation
The given expression can be simplified by canceling out the common factors in the numerator and denominator. The common factors are 2, x, and y. After canceling out these factors, we are left with 4x in the numerator and 5y in the denominator. Therefore, the simplified form of the expression is 4x/5y, which is Option 3.
39.
Expand -5(4x+2)
(A) -20x + 2
(B) -20x- 10
(C) -20x+ 10
(D) -30x
Correct Answer
B. Option 2
Explanation
To expand -5(4x+2), we distribute the -5 to both terms inside the parentheses. This gives us -20x - 10. Therefore, the correct answer is option 2, -20x - 10.
40.
If U = (all letters of alphabet), A ={f, a, k, e} (b.) {s, p, e, a, k} the A ∩ B = ?
Correct Answer
A. {a,e,k}
Explanation
The intersection of sets A and B is the set of elements that are common to both sets. In this case, the elements "a", "e", and "k" are present in both sets A and B. Therefore, the correct answer is {a,e,k}.
41.
2y = 32, find the value of y
Correct Answer
D. 5
Explanation
To find the value of y in the equation 2 to the power of y equals 32, we can rewrite 32 as a power of 2:
32 is equal to 2 to the power of 5.
So, the equation becomes:
2 to the power of y is equal to 2 to the power of 5.
Since the bases are the same, we can set the exponents equal to each other:
y equals 5.
Therefore, the value of y is 5.
42.
Solve the equation 2x -1 = x + 9
(A) x = 5 (B) x = 6
(C) x = 9 (D) x = 10
Correct Answer
D. Option 4
43.
Find the median of 2, 1, 0, 3, 1, 1, 4, 0, 1 and 2.
Correct Answer
C. 1.0
Explanation
To find the median, we need to arrange the numbers in ascending order: 0, 0, 1, 1, 1, 1, 2, 2, 3, 4. Since there are 10 numbers, the middle number will be the 5th number, which is 1. Therefore, the median is 1.0.
44.
If f(x) = 3x² - 5x + 2, what is the value of f(4)?
Correct Answer
C. 38
Explanation
To find f(4), substitute x = 4 into the function. First, calculate 4² = 16. Then, multiply by 3 to get 48. Next, multiply -5 by 4 to get -20. Add 48, -20, and 2: 48 - 20 + 2 = 38. This problem tests understanding of function evaluation and applying the correct order of operations. Errors in exponentiation, multiplication, or sign handling can lead to incorrect answers. Carefully substituting values and simplifying correctly is key to solving function-based algebraic problems accurately.
45.
A rectangular field is 50m long and 30m wide. If a 2m wide pathway is built along the inside boundary, what is the remaining area?
Correct Answer
B. 1,256 m²
Explanation
The total area of the field is 50 × 30 = 1,500 m². Since the pathway runs along the boundary, it reduces both dimensions by 4m (2m from each side). The new dimensions are 50 - 4 = 46m and 30 - 4 = 26m. The remaining area is 46 × 26 = 1,256 m². This problem requires understanding how a border affects area calculations. It is essential to subtract the total reduction in length and width before recalculating. Miscalculating the reduced dimensions can lead to wrong answers, so careful attention to details is important.