find the sum of all three digit natural numbers which are divisible by `7`

Options

A. 5497
B. 5498.5
C. 5499.5
D. 5490

Answer

B

Explanation

Four digit numbers which are divisible by 7 are
1001, 1008, 1015,……,9996
Hence total number of such numbers =1286
`rArr" Medium"=((N/2)^(th)" value"+(N/2+1)^(th)" value")/2=((643)^(th)"value"+(644)^(th)" value")/2`
`=1001+(1285xx7)/2`
`=1001+4497.5`
`=5498.5`