The average of 9 numbers is 35. When one more number is added, the average becomes 36. What is the number added?

💡 Solution & Explanation

Total of the 9 numbers = 9 × 35 = 315. Total of all 10 numbers = 10 × 36 = 360. The new number is the difference: 360 − 315 = 45. Shortcut: new number = new average + (old count × rise in average) = 36 + 9 × 1 = 45.