Permutations and combinations - Quantitative Aptitude (MCQ) questions for Q. 20644

Q.  A person can go from place “P” to “Q” by 7 different modes of transport, but is allowed to return back to “P” by any mode other than the one used earlier. In how many different ways can he complete the entire journey?
- Published on 07 Jul 17

a. 42
b. 30
c. 11
d. 56
e. 65

ANSWER: 42
 
The person can travel from “P” to “Q” in any of the 7 different modes of transport. However, while returning, he cannot use the mode which he used earlier. Thus, while returning, he has the option of only 6 different modes of transport. Hence, the total number of ways would be 7 * 6 = 42.

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