Average, Mixture and Alligation Question 2 - CAT 2022
Manu earns ₹4000 per month and wants to save an average of ₹550 per month in a year. In the first nine months, his monthly expense was ₹3500, and he foresees that, tenth month onward, his monthly expense will increase to ₹3700. In order to meet his yearly savings target, his monthly earnings, in rupees, from the tenth month onward should be:
Step-by-Step Explanation
- Find the Total Target Savings:
Manu wants to save an average of ₹550 per month over 12 months.
Total Savings Target = 550 × 12 = ₹6600
- Calculate Savings from the First 9 Months:
Earnings = ₹4000/month; Expense = ₹3500/month.
Monthly Savings (Months 1–9) = 4000 − 3500 = ₹500
Total Savings in 9 Months = 500 × 9 = ₹4500
- Determine the Budget for the Last 3 Months:
Remaining Savings Needed = 6600 − 4500 = ₹2100
Required Monthly Savings (Months 10–12) = 2100 / 3 = ₹700
Since expenses increase to ₹3700 per month during this period, the required monthly earnings must cover both expenses and target savings:
Required Monthly Earnings = Expenses + Savings = 3700 + 700 = ₹4400
Correct Option: A
💡 FundaMakers Tip:
Break down time-bound targets into two simple ledger columns: Achieved vs. Pending Balance. Once you isolate the pending savings balance required for the final stretch, adding it directly back to the updated expense baseline instantly gives the minimum necessary income without setting up a single multi-variable equation.