Question

which term of A.P 3,8,13,18,...........is 78?

Answer 1

Heya friend!
Rajdeep here...

Let a be the first term and d be the common difference.
Given an = 78...
a = 3
d = 8 - 3 = 5
n = ?

an = a + (n-1)d
=> 78 = 3 + (n-1)5
=> 75 = 5n - 5
=> 5n = 80
=> n = 16

So, 78 is the 16th term in the AP series.

Answer 2

Please mark it as brainliest