Correct Answer - Option 4 : 2376
Concept used:
If the difference between the numbers is constant:
Average = (First term + Last term)/2
Number of terms (n) = 1 + (Last term – First term)/Difference between the numbers
Sum of series = n × Average
Calculation:
31 + 33 + 35 + 37 + ....... + 101
Difference between the numbers = 2
Average = (31 + 101)/2 = 132/2 = 66
⇒ n = 1 + (101 – 31)/2
⇒ n = 1 + 70/2
⇒ n = 1 + 35
⇒ n = 36
Sum of series = 66 × 36
⇒ 2376
∴ The value is 2376.
