Question

The sum of the 8th and 13th terms of an AP is 44 and If its 10th term is three times its 3rd term. Find the sum of 20 terms of the AP.

Answer 1

Answer:

41

Step-by-step explanation:

a+7d+a+12d=44

a+9d=3(a+2d)=a+9d=3a+6d

2a=3d

now from 1st,

2a+19d=44

3d+19d=44

22d=44

d=2

2a=3×2

a=3

and 20th term is

a+19d=3+38=41