If during a one-day period the Q train arrives at the station 30% less frequently than the B train, and the B train arrives 10% less frequently than the F train, then the Q train’s frequency is what percent of the F train’s frequency?
A.27
B.40
C.60
D.63
E.90
我的答案:
If during a one-day period the Q train arrives at the station 30% less frequently than the B train, and the B train arrives 10% less frequently than the F train, then the Q train’s frequency is what percent of the F train’s frequency?