hanumath
Hi,
This is my first post and am glad to be here :-D . This forum certainly rocks.
Need some help in understanding and arriving at the solution for the below problem. Appreciate any help on this.
Q: A boat is to be manned by eight men of whom two can only row on bow side and one can only row on stroke side. In how many ways can the crew be arranged?A) 5760
Thanks,
Hanumath.
Think of it this way:
We assume there are 4 men on the bow side and 4 on the stroke side (which, by the way, is not explicitly mentioned which is a failing of this question)
Of the 8 men, 2, say A and B, must be on the bow side.
1, say S, must be on the stroke side.
For A, there are 4 possible spaces (bow side places). For B, there are 3 possible spaces (one is already occupied by A). For S there are 4 possible spaces (on stroke side). For the fourth guy, there are 5 spots, for the fifth guy, there are 4 spots and so on...
Possible arrangements = 4*3*4*5*4*3*2*1 = 5760
This is what we call the basic counting principle.