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.