DS integers-divisible

a) r is the product of 4 consecutive positive integers.

Multiples of 3 are 3,6,9,12...
any set of 4 positive integers will have a multiple of 3.

say 1,2,3,4 has 3
8,9,10,11 has 9(a multiple of 3)

Hence a) alone is sufficent

b) r < 25
It doesnt matter if r is less than 25 or not.


Hence A is the correct choice

Cheers!
Aks

If the integer is n, 4 consecutive integers become

n n+1 n+2 n+3 and n+4

For any given number, if you consider it as a part of 4 consecutive numbers then you will always be able to divide it by 3

Hence only 1 is sufficient

As a general rule.

If a number is a product of N consecutive numbers, it would be completely divisible by all number from 1 to N.

So if a number is a product of four consecutive numbers, then the number is completely divisible by 1, 2, 3 and 4....

Thanks!