A boat is to be manned by 9 crew with 4 on the stroke side, 4 on the row side and one to steer. There are 11 men of which 2 can stroke only and 1 can row only while 3 can steer only. The number of ways the crew can be arranged for the boat is 

One person for steering can be selected from 3 persons in $3_{{\mathrm{C}}_1}$ ways.

In the remaining 8 people

One person who can row only is to be allotted row side

2  person who can stroke only is to be allotted row side

Now 5 people are remaining.

3 persons to be allotted to row side

2 persons to be allotted stroke side

Total Number of arrangement $=3_{{\mathrm{C}}_1}\times 5_{{\mathrm{C}}_3}\times 4!\times 4!$

$=3\left(10\right)24\times 24=17280$