Question

find the sum of all number between 200 and 400 which are divided by 4​

Answer 1

Answer:

First term of the given A.P. is 200 and last term is 400. Both are divisible by 4. First we have to find out how many numbers from 200 to 400 are divisible by 4. There are 200 numbers from 200 to 400. If we divide 200 by 4 , we get 50.But 200 is also divisible by 4. So total terms are 50+1=51. Now using formula

s = n( first term + last term )/2

s= 51(200+400)2

s= 51x600/2

s= 51 x 300

s = 15300