The average of 14 numbers is 38. When one more number is added, the average becomes 39. What is the number added?

💡 Solution & Explanation

Total of the 14 numbers = 14 × 38 = 532. Total of all 15 numbers = 15 × 39 = 585. The new number is the difference: 585 − 532 = 53. Shortcut: new number = new average + (old count × rise in average) = 39 + 14 × 1 = 53.