Question
The average of 15 numbers is 110. The average of the
first 7 numbers is 98 and the average of the last 7 numbers is 62. What is the 8th number?Solution
Total sum of 15 numbers = 15 × 110 = 1650 Sum of first 7 numbers = 7 × 98 = 686 Sum of last 7 numbers = 7 × 62 = 434 According to question, => 1650 – (686 + 434) = 530
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