Q6 of 85 Page 128

Without adding, find the sum of the following numbers

1 + 3 + 5 + 7 + 9 + 11 + 13 + 15 + 17 =

Given, 9 consecutive odd numbers sum. To find out, the sum of consecutive odd numbers from “1” to “17” without adding.


We have sum of first n odd numbers = n2.


Here, n = 9


⇒ 1 + 3 + 5 + 7 + 9 + 11 + 13 + 15 + 17 = 92


⇒ 1 + 3 + 5 + 7 + 9 + 11 + 13 + 15 + 17 = 81


Hence, the sum of 1 + 3 + 5 + 7 + 9 + 11 + 13 + 15 + 17 without adding = 81


More from this chapter

All 85 →
5

How many numbers lie between the square of the following numbers

107;108

 6

Without adding, find the sum of the following numbers

1 + 3 + 5 + 7 + 9 =

 6

Without adding, find the sum of the following numbers

1 + 3 + 5 + 7 + 9 + 11 + 13 + 15 + 17 + 19 + 21 + 23 + 25 =

 1

Find the square roots of the following numbers by Prime factorization method.

441