Question
The average of three numbers is 60. When three more numbers
are included, the average increases by 6. Find the average of the numbers included.Solution
Sum of the 3 numbers = 60 × 3 = 180
New average = 60 + 6 = 66
Sum of 6 numbers = 66 × 6 = 396
Sum of new 3 numbers = 396 - 180 = 216
Required average = 216 ÷ 3 = 72
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