f(x) = -2x^2 + 24x + 1280
This is a downward turning parabola........we can find the x coodinate of the vertex as
-24/ [ (2 (-2) ] = -24 / -4 = 6
This means that the number of people that maximizes the revenue is 32 - 6 = 26
This is the answer to (2)
And for (1)....the max revenue is
-2(6)^2 + 24(6) + 1280 =
-2(36) + 144 + 1280 = $1352