求两道数学，多谢大家！

谷雨书UID: 2844013

If n is the product of the integers from 1 to 20 inclusive, what is the greatest integer k for which 2*k(2的K次幂，不会打请见谅解) is a factor of n?
A,10
B,12
C,15
D,18
E,20


A circular mat with diameter 20 inches is placed on a square tabletop, each of whose sides is 24 inches long. Which of the following is closest to the fraction of the tabletop covered by the mat?
A,5/12
B,2/5
C,1/2
D,3/4
E.5/6

多谢！！

terryisakidUID: 2522168

D C?

terryisakidUID: 2522168

楼主肯定是没理解正确，所以做错了，其实真的不难。(1)2^18:2^10x2^8 其中2^8来自于6x10x12x14x18中的2,2^10来自于2x4x8x16
(2)问的是被遮住的部份与整个square tabletop面积比

HENRYLIHEUID: 35341

Ｄ　在２０个数字里面找２的因子　然后求和

Ｃ　面积比　１５７/２８８