Question
Given a set of 25 numbers, the overall average is 60.
The first 11 numbers in this set have an average of 48, while the last 15 numbers have an average of 67. What is the value of the 11th number in the sequence?Solution
Sum of all 25 numbers = 25 x 60 = 1500 Let the 11th number be 'x' So, 1500 + x = (11 X 48) + (15 X 67) Or, 1500 + x = 528 + 1005 Or, 1500 + x = 1533 So, x = 33 Hence, option b.
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