Question

Insert 20 A.M. between 2 and 86.

Answer 1

Here 2 is the first term and 86 is the 22^nd term of A.P. 

so  86 = 2 + (21)d

=> d = 4

so the series is 2, 6, 10, 14,......., 82, 86 

∴ required means are 6, 10, 14,...82.