Example 20.23 The expenditure on roads, school and water supply are in the ratio 7: 15 : 2. If the expenditure on roads is GHe2,800, a) find the expenditure on i) schools. ii) water supply b) What is the budget for these three projects? c) The cost of maintaining libraries is GH490.00 and this is met from the expenditure on schools. What percentage, correct to 3 significant figures, of the expenditure on schools is spent on maintaining libraries?​