Question

The average of 13 results is 60. If the average of 1^st 7 results is 59 and that of the last 7 is 61. What will be the 7^th result?
1. 65
2. 75
3. 55
4. 50
5. 60

Answer 1

Correct Answer - Option 5 : 60

Given:

Average of 13 results = 60

Average of 1^st 7 results = 59

Average of the last 7 result = 61

Formula Used:

Average = Sum/Number

Calculations:

As we know,

Average = Sum/Number

⇒ 60 = S/13

⇒ Sum = 780

⇒ Sum of 1^st 7 numbers = 59 × 7 = 413

⇒ Sum of last 7 numbers = 61 × 7 = 427

⇒ 7^th result = Sum of 1^st 7 numbers + Sum of last 7 numbers - Sum of all the results

⇒ (413 + 427 - 780)

⇒ 840 - 780

⇒ 60

∴ The7^th result is 60.