Question

The sum of numbers between 200 and 400 divisible by 7

Answer 1

Answer:

${ \boxed {\boxed {\boxed {\boxed {\rm{ 8729}}}}}}$

Step-by-step explanation:

Hence, Sum of All Natural Numbers divisible by 7 between 200 and 400 is 8729.

Answer 2

Answer:

8729.

Step-by-step explanation:

Numbers between 200 and 400 that are divisible by 7 are 203 , 210.….399.

Here,

a = 203

d = t(2) - t(1)

= 210-203

d = 7

a(n) = 399

To find number of terms , we can use a(n) = a+(n-1)d.

399 = 203 +(n-1)7

399 = 203+7n -7

399-203 + 7 = 7n

203 = 7n

n = 203/7

n = 29

Now , by using Sum to n terms of an AP, we can find the Sum of the numbers. i.e.,

S(n) = n/2(a+l)

S(29) = 29/2(203+399)

= 29/2(602)

=29(301)

S(29) = 8729.