Question

Which term of A.P. 5, 15, 25 ………… will be 130 more than its 31st term?

Answer 1

The given A.P is 5, 15, 25,...

Here, a = 5 and d = 15 - 5 = 10

Now `t_31 = a + 30d = 5 + 30 xx 10 = 5 + 300 = 305`

Let the required term be nth term.

`∴ t_n - t_31 = 130`

`=> [a + (n - 1)d] - 305 = 130`

=> 5 + (n - 1)(10) = 435

=> n - 1 = 43

=> n = 44

Thus reuired term = 44^th term.