Question
The average of 12 numbers is 120. The average of the
first 7 numbers is 75 and the average of the last 4 numbers is 53. What is the 8th number?Solution
Total sum of 12 numbers = 12 × 120 = 1440 Sum of first 7 numbers = 7 × 75 = 525 Sum of last 4 numbers = 4 × 53 = 212 According to question, => 1440 – (525 + 212) = 703
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