Question
The average of three numbers is 66. When three more
numbers are included, the average increases by 6. Find the average of the numbers included.Solution
Sum of the 3 numbers = 66 × 3 = 198
New average = 66 + 6 = 72
Sum of 6 numbers = 72 × 6 = 432
Sum of new 3 numbers = 432 - 198 = 234
Required average = 234 ÷ 3 = 78
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