Mary has 40% fewer marbles than Jolie. If they combine all their marbles in a single bag, what percent of the marbles in the bag are Jolie's?
M = Mary’s marbles, J = Jolie’s marbles
M = 0.6J
fraction J/(M + J) = 1/(0.6 + 1) = 0.625
percent = 0.625*100 = 62.5%