Question

The crew of apollo 17 consisted of 2 pilots and a geologist. Suppose that nasa had actually trained 9 pilots and 4 geologists as candidates for the flight. How many different crews could they have assembled?

Answer 1

They could have assembled total 336 different possible crews.

Explanation

Total number of trained pilots is 9 and geologists is 4.

The crew should be consisted of 2 pilots and 1 geologist. That means, 2 pilots are chosen from total 9 and 1 geologist is chosen from total 4.

Number of ways for choosing 2 pilots from 9 $= ^9C_{3} =84$ and

Number of ways for choosing 1 geologist from 4 $=^4C_{1}= 4$

So, the total possible number of different crews they could have assembled $=84*4= 336$