Question
The incomes of ‘X’, ‘Y’ and ‘Z’ are in the
ratio 3:4:5, respectively and the average of their incomes is Rs. 12,000. If ‘X’, ‘Y’ and ‘Z’ spend 60%, 50% and 70% of their incomes respectively, then find the average of their expenditures.Solution
ATQ,
Sum of incomes of ‘X’, ‘Y’ and ‘Z’ = 12000 × 3 = Rs. 36,000
So, income of ‘X’ = 36000 × (3/12) = Rs. 9,000
Income of ‘Y’ = 36000 × (4/12) = Rs. 12,000
Income of ‘Z’ = 36000 × (5/12) = Rs. 15,000
Expense of ‘X’ = 9000 × 0.6 = Rs. 5,400
Expense of ‘Y’ = 12000 × 0.5 = Rs. 6,000
Expense of ‘Z’ = 15000 × 0.7 = Rs. 10,500
Therefore, required average = (5400 + 6000 + 10500) ÷ 3 = Rs. 7,300
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