Out of a group of seven ees and five mes, a committee consisting of three ees and two mes is to be formed. in how many ways can this be done if:

This is a combination problem. 
Number of ways to select three ees from seven ees are = 

Number of ways to select two mes from five mes are =

For each of the 35 groups of ees 10 groups of mes can be formed. So the total number of groups that can be formed will be 35 x 10 = 350

So there are 350 ways to form such a committee with three ees and two mes from a group of seven ees and five mes.