Question
There are 15 natural numbers whose average is 30.6. The
average of the first 8 numbers is 28, and the average of the last 8 numbers is 33. Find the eighth number in this sequence.Solution
Sum of all 15 natural numbers = 30.6 X 15 = 459 Required, eighth number = 8 X 28 + 8 X 33 - 459 = 224 + 264 - 459 = 488 - 459 = 29
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