The average of five consecutive odd numbers is m. if the next three odd numbers are also included, then what is the increase in the average?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is Option 4 i.e. 3.
| Understanding/Application |
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Let the first odd no. be x. Then 5 consecutive odd number will be x, x + 2, x + 4, x + 6, x + 8 whose sum is 5x + 20 and average will be x + 4. M = x + 4 x = M - 4 The next 3 odd numbers will be x + 10, x + 12, x + 14 whose sum is 3x + 36. The sum of 8 numbers is (5x + 20) + (3x + 36) = 8x + 56 |
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The new average = 8(x + 7)/8 = x + 7 on putting value of x = M - 4 M - 4 + 7 = M + 3 The new average is M + 3 Increment in the average = M + 3 - M = 3 |