4th Class
Mathematics
Factors and Multiples
Question Bank
Multiples and Factors
question_answer
Direction: Factors of a number which are prime are called its prime factors. Factors of 36 are: 1, 2, 3, 4, 6, 9, 12, 18. Prime factors of 36 are: 2, 3. A number can be written as a product of its prime factors, e.g.\[36=2\times 2\times 3\times 3\]. A factorization in which every factor is prime is called prime factorization of the number. Two numbers are co-prime if they have only 1 as the common factor. Based on the information given above answer the following questions. Which one of these are co-primes?
A)24, 32
B)18, 12
C)9, 16
D)60, 84
Correct Answer:
C
Solution :
9, 16 are co-primes \[9=3\times 3\] \[16=4\times 4\] 9 and 16 have only 1 as the common factor.