Question

In an ap 12th term is 13 and sum of first four term is 24 then find ap

Answer 1

A12=a+12d=13
=>a=13-12d
S4=4/2 ×[2a+3d]=24
=>2a+3d=12
=>2(13-12d)+3d=12
=>26-24d+3d=12
=>21d=14
=>d=2/3
a=13-12d=13-8=5
A.P. 5,17/3,19/3,7...