Question

arithmetic progression
only 11 no.

Answer 1

AP formed = 3,7,11,15..........
Hope this helps you....

Answer 2

let the first term be a a,5=a+4d=19 a,18-a,13=20 => 17d-12d=20 => 5d=20 => d=4 a,5=19 => a+4*4=19 => a=3 ap;;;;; 3,7,11,15,19........