Question

find the sum of all numbers between 200 and 500 which are divisible by 9​

Answer 1

Answer:

15050

Step-by-step explanation:

Let a be the first term and d be the common difference.

The first term between 200 and 500 divisible by 7 is 203 and the last term is 497.

Therefore the first term a = 203 and the common difference d = 7.

We know that sum of n terms of an AP an = a + (n - 1) * d

                                                                 497 = 203 + (n - 1) * 7

                                                                 497 = 203 + 7n - 7

                                                                 497 = 7n + 196

                                                                 497 - 196 = 7n

                                                                 301 = 7n

                                                                 301/7 = n

                                                                 n = 43.

Therefore, there are 43 integers between 200 and 500 which are divisible by 7.

Now to find the sum use this formula,

$S_{n} = \frac{n}2} (a + l)$

here put n = 43, a = 203 and l = 497

WE get, 15050 as sum

MARK AS BRAINLIEST