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The average age of 30 students of a class is 14 years 4 months. After admission of 5 new students in the class the average becomes 13 years 9 months. The youngest one of the five new students is 9 years 11 months old. The average age of the remaining 4 new students is
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- 11 years 2 months
- 13 years 6 months
- 12 years 4 months
- 10 years 4 months
- 11 years 2 months
Correct Option: A
Given that , The average age of 30 students = 14 years 4 months.
Total age of initial 30 students = 14 years 4 months × 30 = 430 years
After admission of 5 new students, the average of 35 students = 13 years 9 months.
Total age of 35 students = 13 years 9 months × 35
Total age of 35 students = (455 + 26) years 3 months = 481 years 3 months
∴ Total age of 4 new students = 481 years 3 months – 430 years – 9 years 11 months = 481 years 3 months – 439 years 11 months
Total age of 4 new students = 41 years 4 months
| ∴ Required average = | 41 years 4 months |
| 4 |
Required average = 10 years 4 months
