Question

Choose the factor of 90 which is not prime.

• A. 2
• B. 6
• C. 7
• D. 12

Answer 1

The correct option is B 6

Factor pairs of 90 = 1 x 90, 2 x 45, 3 x 30, 5 x 18 , 6 x 15, 9 x 10
So all the factors of 90 = 1, 2, 3, 5, 6, 9, 10, 15, 18, 30, 45, 90
Apart from 2, 3, 5 all the factors are not prime.
In the given options 2 and 6 are the factors
So option B is the correct answer.