How many three-digit natural numbers are divisible by 7?

Asked by Topperlearning User | 20th Nov, 2013, 10:08: AM

Expert Answer:

Three digit numbers divisible by 7 are

105, 112, 119, ..., 994

This is an AP with first term (a) = 105 and common difference (d) = 7

Let an be the last term.

an = a + (n - 1)d

994 = 105 + (n - 1)(7)

7(n - 1) = 889

n - 1 = 127

n = 128

Thus, there are 128 three-digit natural numbers that are divisible by 7.

Answered by  | 20th Nov, 2013, 12:08: PM