Question : The average of 15 results is 21. The average of the first 7 of those is 21 and the average of the last 7 is 20. What is the 8th result?
Option 1: 25
Option 2: 31
Option 3: 28
Option 4: 22
Correct Answer: 28
Solution :
The average of 15 results is 21, which means the sum of all 15 results is 15 × 21 = 315.
The average of the first 7 results is 21, which means the sum of the first 7 results is 7 × 21 = 147.
The average of the last 7 results is 20, which means the sum of the last 7 results is 7 × 20 = 140.
So, the 8th result = Sum of all 15 results – Sum of first 7 results – Sum of last 7 results
= 315 – 147 – 140
= 28
Hence, the correct answer is 28.
Related Questions
Know More about
Staff Selection Commission Sub Inspector ...
Result | Eligibility | Application | Selection Process | Cutoff | Admit Card | Preparation Tips
Get Updates Brochure
Your Staff Selection Commission Sub Inspector Exam brochure has been successfully mailed to your registered email id “”.
