A group of 5 boys and 4 girls are to be photographed. How many ways can the photograpg be arranged with the girls in the front row, and the boys in the back row?


A club has 10 members. In how many ways can they shoose a committee of 3 members?

Have you attempted these questions on your own first?
You won't learn much unless you've thought about these before asking us.

Yes.. I have attempted. For the first one I had gotten 30 ways

For the second, I didn't get an answer

The second is extremely simple if you understand the answer to the lottery question you asked. You have 10 people from which you can selecct and you must select 3 members. 10 choose 3.

For the question about the class picture:

First think about how just the girls can be arranged. You should be able to write all the different possibilities. You'll find that there are 4! Ways of arranging just the girls in the front row. Then you'll find that there are 5! Ways of arranging the boys in the back row. Since all of the girl arrangements can go with all of the guy arrangements, there are 4!x5! Ways of setting up the photo. 2,880 ways.