A grant is shared among three heads. The third head takes 40% of the grant, and the first head takes 50% more than the second. What per cent of the grant does the first head take?

The first two heads share 100 - 40 = 60% between them. If the second takes s, the first takes 1.5s, so 2.5s = 60, giving s = 24 and first = 36%. Check: 36 + 24 + 40 = 100. 30% splits the 60 down the middle, which would be right only if the two heads took equal amounts. 24% is the second head's share, and 40% is the third head's.