The ratio of income of 'M' to that of 'N' is 4:5. Sum of

Solution

ATQ, Let the income of 'M' and 'N' be Rs. '4p' and Rs. '5p', respectively. Let the savings of 'N' be Rs. '9q'. Savings of 'M' = 1.35 × 9q = Rs. '12.15q' Sum of expenditure of 'M' and 'N' = (4p - 12.15q) + (5p - 9q) = 90000 Or, 9p - 21.15q = 90000 ....(i) ATQ, 0.50 × 9p = 4p - 12.15q Or, 4.5p = 4p - 12.15q Or, 4p - 4.5p = 12.15q Or, -0.5p = 12.15q Or, p = (-12.15q / -0.5) = 24.3q Put the value of 'p' in equation (i), we get, 9 × 24.3q - 21.15q = 90000 Or, 218.7q - 21.15q = 90000 So, q = (90000 / 197.55) = 455.57 Or, 'p' = 24.3q = 24.3 × 455.57 = 11064 Income of 'N' = 5p = 5 × 11064 = Rs. 55,320