Question
Average of first 2 numbers is twice the average of next 4
numbers. If the average of all 6 numbers is 18, find the sum of the last 4 numbers.Solution
Let the sum of the last 4 numbers be 'n'.
(sum of first 2 numbers) ÷ 2 = 2 × (n/4)
⇒ Sum of first 2 numbers = n
Total sum = n + n = 2n
Average of 6 numbers = 2n ÷ 6 = 18
⇒ 2n = 108
⇒ n = 54
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