A trust gives 40% of its yearly fund to a school and 25% of what is then left to a clinic. The clinic's grant is what per cent of the school's grant?

Take the fund as 100. School = 40, leaving 60; clinic = 25% of 60 = 15. The question compares the clinic with the SCHOOL, not with the fund: 15/40 = 0.375 = 37.5%. 15% is the clinic's share of the fund, which is the figure most people stop at. 10% is 25% of 40, taking the clinic's rate on the school's grant instead of on the leftover. 62.5% is 25/40 - dividing the two RATES, which are shares of different bases and cannot be compared directly.