1.
Which number below is the greatest common factor, or GCF, of the numbers 24 and 36?
Correct Answer
C. 12
Explanation
The greatest common factor (GCF) is the largest number that divides evenly into two or more numbers. In this case, we need to find the GCF of 24 and 36. We can find the GCF by listing the factors of each number and finding the largest number that appears in both lists. The factors of 24 are 1, 2, 3, 4, 6, 8, 12, and 24. The factors of 36 are 1, 2, 3, 4, 6, 9, 12, 18, and 36. The largest number that appears in both lists is 12, so it is the GCF of 24 and 36.
2.
How many factors does a Prime number have?
Correct Answer
B. 2
Explanation
A prime number is defined as a number that is greater than 1 and can only be divided evenly by 1 and itself. Therefore, a prime number only has two factors: 1 and the number itself. This is because dividing the prime number by any other number would result in a remainder, indicating that it is not a factor. Therefore, the correct answer is 2.
3.
The number 1 is _______
Correct Answer
D. Neither a Prime nor Composite number
Explanation
The number 1 is neither a prime nor a composite number. A prime number is a number greater than 1 that is divisible only by 1 and itself, while a composite number is a number greater than 1 that has factors other than 1 and itself. Since 1 does not meet the criteria for either definition, it is categorized as neither prime nor composite.
4.
Which of the following is a multiple of 16?
Correct Answer
A. 64
Explanation
64 is a multiple of 16 because when 16 is multiplied by 4, the result is 64.
5.
Of the following list of numbers: 2,3,4,7,8,11,12, which are Composite numbers?
Correct Answer
D. 4,8,12
Explanation
Composite numbers are numbers that have more than two distinct positive divisors (i.e., they are divisible by numbers other than 1 and themselves). In the given list:
4 (divisors: 1, 2, 4)
8 (divisors: 1, 2, 4, 8)
12 (divisors: 1, 2, 3, 4, 6, 12)
All have more than two divisors, making them composite numbers. The other numbers (2, 3, 7, 11) are prime.
6.
Which of the following correctly lists the factors of the number 28?
Correct Answer
B. 1,2,4,7,14,28
Explanation
The factors of a number are the numbers that can be multiplied together to get that number. In this case, the factors of 28 are 1, 2, 4, 7, 14, and 28 because each of these numbers can be multiplied with another number to equal 28.
7.
Mr. Schorr has every 3rd day off in November. Mr. Lawson has every 5th day off in November. Which date is the first time Mr. Schorr and Mr. Lawson have a day off together so they can hang out?
Correct Answer
C. November 15
Explanation
Mr. Schorr has a day off every 3rd day in November, while Mr. Lawson has a day off every 5th day in November. To find the first time they have a day off together, we need to find the least common multiple of 3 and 5. The least common multiple of 3 and 5 is 15. Therefore, the first time they have a day off together is on November 15.
8.
Which of the following is a prime number?
Correct Answer
C. 7
Explanation
A prime number is a number that is only divisible by 1 and itself. In this question, out of the given options, only 7 meets this criteria. 12, 22, and 4 are all divisible by numbers other than 1 and themselves, making them composite numbers. Therefore, the correct answer is 7.
9.
Which of the following lists the prime factorization of the number 28?
Correct Answer
B. 2,2,7
Explanation
The prime factorization of a number involves breaking it down into its prime factors. In this case, the number 28 can be broken down into the prime factors 2, 2, and 7.
10.
Which number below is a common factor of both 24 and 36?
Correct Answer
B. 12
Explanation
The number 12 is a common factor of both 24 and 36 because it is a number that can divide evenly into both 24 and 36 without leaving a remainder.
11.
Which of these is not the factor of the number 12?
Correct Answer
A. 5
Explanation
The number 5 is not a factor of 12 because a factor of a number is a whole number that can be divided evenly into that number. In the case of 12, the factors are 1, 2, 3, 4, 6, and 12. Since 5 is not one of these factors, it is not a factor of 12.
12.
Which number is a factor of 50?
Correct Answer
D. 25
Explanation
The factor of a number is a number that divides evenly into that number. In this case, the factors of 50 are 1, 2, 5, 10, 25, and 50. Among the given options, only 25 is a factor of 50.
13.
A prime number has only ____ factors.
Correct Answer
C. Two
Explanation
A prime number has only two factors, which are 1 and itself. This means that a prime number cannot be divided evenly by any other number except for 1 and itself. For example, the factors of the prime number 7 are 1 and 7. Therefore, the correct answer is Two.
14.
Which of these is a factor of 48?
Correct Answer
A. 12
Explanation
12 is a factor of 48 because it divides evenly into 48 without leaving a remainder. In other words, 48 can be divided by 12 to give a whole number result.
15.
Which of these is not a factor of number 18?
Correct Answer
B. 8
Explanation
The number 18 can be divided evenly by 6, 9, and 18, but not by 8. Therefore, 8 is not a factor of 18.