There are 8! possible combinations, or 8p8, and there is only 1 that has them in order from oldest to youngest, so the answer is A.
Part 1:
Step 1:
Find the value of G(16)
Using the equation for g(x) =√x, replace x with 16 and solve:
g(16) = √16 = 4
Step 2:
Now using the answer for g(16) replace x in the equation fir f(x) with 4 and solve:
f(x) = x +2
f(4) = 4+2 = 6
Part 2:
following the same steps as part 1:
f(g(x)) would be replacing x in the equation ofr f(x)with the equation for g(x)
f(g(x)) = √x +2
