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
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?