Question

How many numbers are there in between 55 and 4495, which are divisible by both 5 and 3?

Answer 1

The first number after 55, that is divisible by 5 and 3 is 60.

The last number before 4495, that is divisible by 5 and 3 is 4485.

We have an AP whose first term is a= 60 and the last term is 4485, the common difference being 15.

Tn = a+(n-1)d, or

4485 = 60 + (n-1)*15, or

4485–60 = 4425 = (n-1)*15, or

(n-1) = 4425/15 = 295, or

n = 295+1 = 296

So the ans is 296