Multiple choice

The mean of 15 numbers is 60. If the mean of first 8 results is 59 and that of last 8 results is 63, find the 8th result.

  1. 86

  2. 104

  3. 50

  4. 76

  5. 62
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

It is correct answer.Sum of 15 results =(15*60) = 900Sum of First 8 results=(8*59) = 472Sum of Last 8 results= (8*63) = 504It is quite obvious that the 8th result is included twice.Therefore,value of the 8th result = Sum of 1st eight results + Sum of last eight results - Sum of 15 results                                                            =  472 + 504 - 900 = 76

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