Question

Which term of the A.P. 3, 8, 13, 18, 23 ......, is 98?

Answer 1

Here $$a = 3$$ and $$d = 8 - 3 = 5$$. 

Let the term be nth. $$3 + (n - 1) \times 5 = 98$$. 

So $$5n - 2 = 98$$, giving $$n = 20$$. 

Hence 98 is the 20th term.