AP EAMCET202018 Sep 2020Evening ShiftMathematicsPermutation and CombinationActual
The crew of an 8-oar boat is to be chosen from 12 men, of whom 3 can row on the stroke side only. The number of ways in which the crew can be arranged is
Options
- A( ^9 C ₄ ^8 C ₃ 3 ) ! ( 4 ) !
- B( ^9 C ₄ ^8 C ₄ 4 ) ! ( 4 ) !
- C( ^8 C ₃ ^8 C ₃ 4 ! 3 ) !
- D( ^9 C ₄ ^9 C ₄ 4 ) ! ( 4 ) !
Correct answer
B. ( ^9 C ₄ ^8 C ₄ 4 ) ! ( 4 ) !
Step-by-step solution
Crew side (=4 4 ) ! ways Stroke side (=4 4 ) ! ways Total number of ways (= ^9 C₄ ^8 C₄ 4 ! 4 ! ) Hence, option (b) is correct.