Question

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

Answer 1

Answer:

128

Step-by-step explanation:

This can be solved using AP

The first 3 digit no. divisible by 7 = 105

The last 3 digit no. divisible by 7 = 994

l = a + (n-1)d

l = 994

a = 105

d = 7

And we have to find n.

994 = 105 + (n-1)7

Solving it, we get n = 128

Answer 2

Answer:

128

Step-by-step explanation:

AP > 105,112.........994

a=105 , d=7 , $a_{n}$ =994

$a_{n}$ = a + (n-1)d

994 = 105 +(n-1)7

142 = 15 + n - 1

128 = n