A college has raised 75% of the amount it needs for a new building by receiving an average donation of $60 from the people already solicited. The people already solicited represent 60% of the people the college will ask for donation. If the college is to raise exactly the amount needed for the new building, how much must the remaining people donate per person?

Let the required donation per persion be D. People remaining to be solicited = 100 - 60 = 40% Funds remaining to receive = 100 - 75 = 25% ATQ,   (D x 40%) / ($60 x 60%) = 25% / 75% or,  D = 25% x ($60 x 60%) / (75% x 40%) = $30