Q4:
If n is the product of the integers from1 to 20 inclusive, what is the greatest integer k for
which 2k is a factor of n?
A. 10
B. 12
C. 15
D. 18
E. 20
Answer:
1*2*3*4*5。。。。*20
我是笨方法把含有2因子个数一个个加的
2,4,6,8,10,12,14,16,18,20=
1+2+1+3+1+2+1+4+1+2=18
以下是引用mary1在2004-12-11 8:55:00的发言:1*2*3*4*5。。。。*20
我是笨方法把含有2因子个数一个个加的
2,4,6,8,10,12,14,16,18,20=
1+2+1+3+1+2+1+4+1+2=18
谢谢
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