Question

If k+1 is a multiple of 5 and k+3 is a multiple of 3. What is k^2?

Answer 1

Step-by-step explanation:

Since 'm' and 'n' are primes, In order for k to be a multiple of 3 either 'n' or 'm' must be 3. Also, In order to be a multiple of 9 the product must have two 3's as factors.

A) No. 'm' could be 3 or 'n' could be 3 we don't know which one

B) No. Same logic as above.

C) No. 'm' and 'n' could both be 3 in which case it would work. But they could also be '5' and '7' or some other pair of primes.

D) No. n^2 could be 3^2 or it could be 5^2 (or some other prime number)

E) Correct Answer. Since 3 must be one of the numbers, squaring the product must yield 9 as a factor.