The average of 9 numbers is 40. If the average of the first five numbers is 38 and that of the last five is 50, then what is the fifth number?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 80
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Understanding |
Application |
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Average of 9 numbers = 40 Average of first 5 = 38 Average of last 5 = 50
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Sum of all 9 numbers = 9 × 40 = 360 Sum of first 5 numbers = 5 × 38 = 190 Sum of last 5 numbers = 5 × 50 = 250 5th number = (190 + 250) – 360 = 440 – 360 = 80 |