Bunuel wrote:

Official Solution:

Which of the following numbers is equal to \(8!\) ?

A. 38910

B. 39340

C. 39980

D. 40320

E. 40450

Backsolve. \(8!\) has to be divisible by 3. Choices B, C, and E are out for this reason. \(8!\) has to be divisible by 4. Hence choice A is out. The only viable option is choice D.

Answer: D

no need to backsolve.

no need to check the divisibility.

how about this=>

since 6!=720

8!=720*8*7=> 720*56=> 72*56*10

here the tens digit must must be 2

hence option D

yes, I also looked for tenth digit unit of answer choices and then recognized they're totally different. So just leave out 5*2=10, multiply unit digit of 7*8 = 56*6=6*4*3=2, only choice D