Math Probaility - Lining up for a photograph?

Im not good in calculations since i have no calculator so, i guess, what i can give to you is th idea. For that problem, use binomial theorem. And because the only concern is the combination of the committee, then, we dont need to find the probability of the arrangement. So i guess the statement "ascending or descending order of ages is not important. My answer maybe wrong but i am hoping that this can help build up your ideas to solve the problem. Take care..