18520. This is the only option with last two digits divisible by 8
Which of the following numbers is divisible by 8?
Options:
(A) 10021
(B) 17511
(C) 26778
(D) 18520
(E) 26711
(D)

Let the boys are X, then girls are 7X, total = X+7X = 8X
So it should be multiple of 8, 30 is not a multiple of 8.
The no. of girls in a class are seven times the no. of boys, which value cannever be the of total students?
Options:
(A) 23
(B) 25
(C) 30
(D) 36
(E) 39
(C)

125^10 = (5^3)^10 = 5^30
What is the greatest positive integer x such that 5^x is a factor of 125^10?
Options:
(A) 5
(B) 9
(C) 10
(D) 20
(E) 30
(E)