推 candyme:Thanks for ur solution:) 01/13 18:27
※ 引述《candyme ()》之銘言：
: 15.
: Tanks A and B are each in the shape of a right circular cylinder.
: The interior of tank A has a height of 10 meters and a circumference
: of 8 meters and a circumference of 10 meters. The capacity of tank A
: is what percent of the capacity of tank B ?
: A.75%
: B.80%
: C.100%
: D.120%
: E.125%
: ANS: B
This question is incomplete.
: 16.
: Meg and Bob are among the 5 participants in a cycling race. If each
: participant finishes the race and no two participants finish at the
: same time, in how many different possible orders can the participants
: finish the race so that Meg finishes ahead of Bob ?
: A.24
: B.30
: C.60
: D.90
: E.120
: ANS:C
: Thanks for your help!!!
4!+C3取1*3!+C2取1*3!+3! =24+18+12+6 =60
^^^^^^^^Meg as Rank2, Bob can be one of three participants behind, and
multiple premutation of other 3 players.
Logic: First decide the rank of Meg and Bob, then consider the premutation of
other 3 participants.
***Hope this helps to answer.
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