Question

the monthly income of A and B are in the ratio 3: 4 and their monthly expenditure are in the ratio of 7:5 of each save 15,000 per month, find their monthly incomes

Answer 1

Income of A : B = 3:4

Expenditure A:B = 5:7

savings = 15000

income = expenditure + savings

let expenditure be x so 5x:7x

(5x+15000) / (7x+15000) = 3/4

20x + 60000 = 21x + 45000

x = 15000

expenditure = 5x and 7x so

Expenditure of A = 5 x 15000 = 75000

Expenditure of B = 7 x 15000 = 105000

Income of A = 75000 + 15000 = 90000

Income of B = 105000 + 15000 = 120000