In how many ways E can the crew of a ten oared boat be arranged ,when of the ten persons available, 2 of whom can row only on the bow side and 3 of whom can row only on the stroke side?  Choose the correct choice
A) 1. 10!/(2! * 3!)  B) 2. 10!/(8! * 7!)  C) 3. 5!/(3! * 2!)  D) 4. (5!)^3/(3! * 2!)  E) 5. 5!/(8! * 7!)
Ans is D.   Going by the assumtion that both the Bow side and Stroke side will have 5 person each.   Five(3+2) of them had allready been selected(according to their preference), so from the remaining 5 we have to select 2 for the stroke side or 3 for the bow side.   and the 5 crew of each side can be arranged in 5! ways.E   Hence answer is 5C3 * 5! * 5!= (5!)^3/ 3!2!.4. (5!)^3/(3! * 2!)
<result>D</result>
In how many ways E can the crew of a ten oared boat be arranged ,when of the ten persons available, 2 of whom can row only on the bow side and 3 of whom can row only on the stroke side?