If you count from 1to100,how many 7's will you pass on the way?A.10B.11C.19D.20E.21

问题描述:

If you count from 1to100,how many 7's will you pass on the way?
A.10
B.11
C.19
D.20
E.21

从70 到79 共用了10个7, 另外 7 到67是7个, 80到100当中还有2个,共19个

20个..我数过了...