Correct Answer - Option 2 : 310
Given:
There are some consecutive even numbers and their average is 310
Concept Used:
When number of observations are odd, then average is same for first and last, second and second last, third and third last,……., so on.
Calculation:
From concept above, the average of second and second last number is 310 = Average of all numbers
Example:
2, 4, 6, 8, 10, 12, 14
Total terms are odd, average of terms is 8
Sum of first and last = 2 + 14 = 16
Average of first and last = 16/2 = 8 = Average of all terms
Sum of second and second last terms = 4 + 12 = 16
Average of second and second last terms = 16/2 = 8 = Average of all terms
Similarly for third and third last term, average will be 16/2 = 8 = Average of all terms
This is applicable only when the terms are consecutive or the terms have same common difference. (If they are in AP)
