Quantitative Aptitude • Ratio, Average & MixtureMedium
The average of 9 numbers is 24. When one more number is added, the average becomes 29. What is the number added?
A. 29
B. 45
C. 34
D. 74✓ Correct Answer
💡 Solution & Explanation
Total of the 9 numbers = 9 × 24 = 216. Total of all 10 numbers = 10 × 29 = 290. The new number is the difference: 290 − 216 = 74. Shortcut: new number = new average + (old count × rise in average) = 29 + 9 × 5 = 74.
More Quantitative Aptitude Ratio, Average & Mixture questions
- The ages of A and B are in the ratio 4 : 5. After 10 years, the ratio of their ages will be 22 : 25. What is…
- The ages of A and B are in the ratio 4 : 5. After 3 years, the ratio of their ages will be 31 : 38. What is…
- A 80-litre mixture contains milk and water in the ratio 4 : 1. How many litres of water must be added to make…
- What is the average of the first 47 odd numbers?
- In what ratio must tea leaves costing ₹53 per kg be mixed with tea leaves costing ₹78 per kg, so that the…