The average age of 5 employees is 30. When a new employee joins, the average becomes 31. How old is the new employee?
Correct answer: D. 36
The 5 employees total 5 × 30 = 150 years. With 6 employees the total is 6 × 31 = 186. The new employee is 186 − 150 = 36 years old.
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