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A courier has to make 5 stops on his route, designated A,B,C,D, and E.
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Updated on: 06 Aug 2023, 08:35
Updated on: 06 Aug 2023, 08:35
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Question Stats:
33% (02:16) correct
66% (02:36) wrong based on 3 sessions
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A courier has to make 5 stops on his route, designated A,B,C,D, and E. How many distinct routes can he take if he must stop at A sometime before D
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60
Re: A courier has to make 5 stops on his route, designated A,B,C,D, and E.
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07 Aug 2023, 03:01
07 Aug 2023, 03:01
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Essentially you have permutation because A and D are fixed
Therefore you pick up TWO letters from 5. Fundamental counting principle
\(\frac{n!}{(n!-r!) }\)
\(\frac{5!}{2! }= \frac{5*4*3*2*1}{2*1} =60\)
Therefore you pick up TWO letters from 5. Fundamental counting principle
\(\frac{n!}{(n!-r!) }\)
\(\frac{5!}{2! }= \frac{5*4*3*2*1}{2*1} =60\)
Re: A courier has to make 5 stops on his route, designated A,B,C,D, and E.
[#permalink]
07 Aug 2023, 03:01
07 Aug 2023, 03:01
1
Expert Reply
