求一道数学，多谢大家！

tingting520

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

painsper

2，4，6，8，10，12，14，16，18，20数一下一共含有多少个2

tingting520

多谢楼上的同学，还有一道请教一下哈
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
是圆的面积/正方形的面积吗？

painsper

对，是圆的面积比正方形的面积

tingting520

可是我算不出答案呢同学解答下好吗

painsper

100pie／（24＊24），我看了一下，大概等于1／2吧。