Question

the sum of all multiples of 7 between 0 and 500 is

Answer 1

a=7 and d=7 an=497 then n=71
sn=n/2 (2a+(n-1)d)
sn=71/2(14+490)
sn=71(7+245)
sn=71(252)
sn=17892

Answer 2

Answer:

The sum of all multiples of 7 between 0 and 500 is 17892

Step-by-step explanation:

To Find :The sum of all multiples of 7 between 0 and 500

Solution:

Multiples of 7 between 0 and 500 = 7,14,21,..........,497

This forms an AP

First term = a = 7

Common difference= 14-7 = 21-14 = 7

Formula of nth term = $a_n=a+(n-1)d$

So, $497=7+(n-1)7$

$497-7=(n-1)7$

$490=(n-1)7$

$70=(n-1)$

$71=n$

Formula of first n terms = $S_n=\frac{n}{2}(a+a_n)$

So,the sum of all multiples of 7 between 0 and 500=$\frac{71}{2}(7+497)$

                                                                                    =$17892$

Hence the sum of all multiples of 7 between 0 and 500 is 17892