Question

Find the sum of all three diGit number which are divisible by 7

Answer 1

3-digit numbers divisible by 7:

First = 105

Last = 994

Number of terms:

N = (Last - First)/(7) + 1 = 128

Sum of the terms:

S = (128/2)×(First + Last) = 64×(105 + 994)

S = 70336

ANSWER:

sum = 70336