The average of 60 student's results is 38. If the average of the first 22 students is 36, and that of the last 32 students is 32, then the average result of the remaining students is:
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e 77.33
| Understanding | Application |
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Average = sum of observations / number of observations ⇒ Sum of observations = average × number of observations |
⇒ the sum of all students = 60 × 38 ⇒ 2280 ⇒ the sum of the first 22 students = 22 × 36 ⇒ 792 ⇒ the sum of the last 32 students = 32 × 32 ⇒ 1024 The sum of rest = 2280 - (1024 + 792) ⇒ 464 Average = 464 / 6 = 77.33 |