Question

The sum of 15 terms of an ap is 495 and 5th term is 21

Answer 1

please mark me as brainlist

Step-by-step explanation:

Assume that it's an arithmetic sequence. a+4d = 21 => a = 21–4d. 495 = (2a+14d)(15)/2 = (42+6d)(15)/2 = 315 + 45d.