Question

How many three digit natural numbers are divisible by 5?
tn= a+ (n-1)d​

Answer 1

Answer:

180 three digit numbers are divisible by 5...

Answer 2

Three digits number divisible by 5 are:

AP: 100, 105,....995

Here, a = 100; d = 5; an = 995

We know that,

an = a + (n-1) d

=> 995 = 100 + (n-1) 5

=> 995 = 100 + 5n - 5

=> 995 - 95 = 5n

=> 900 = 5n

=> n = 900/5

=> n = 180

Therefore, 180 three digit numbers are divisible by 5