Question

Find the sum of the odd numbers between 0 and 50.NCERT Class XMathematics - MathematicsChapter _ARITHMETIC PROGRESSIONS

Answer 1

The addition done is from 1,3,5,7,9,11 etc until 49 and The answer is 635

Answer 2

Solution :

The odd numbers between 0 and 50 are 1, 3, 5, .. , 49. They form an AP and there are 25 terms.

∴ Their sum = $\frac{25}{2} (1 + 49) = \frac{25}{2} \times 50$

                    = 25 × 25 = 625