Question

Find the value of a25 - a15 for the AP: 6, 9, 12, 15, ………..

Answer 1

common difference= 9-6=3

a20-a15=a+19d-(a+14×d)

6+19×3-(6+14×3)

6+57-(6+42)

63-48=15

thus the answer is 15

Answer 2

Answer:

$a25 - a15 = 30$