Question

If the sum of 11 consecutive odd number is 253 find the first term

Answer 1

Let the first term be a
Common difference is 2
Number of terms is 11
Sum is 253
$\frac{11}{2} (2 \times a + (11 - 1) \times 2) = 253 \\ a + 10 = 23 \\ a = 13 \:$