Question

If 4 times the fourth term of an A.P. is equal to 18th term, then find its 22nd term ?

Answer 1

Answer:

Let 1st term A

Common difference = d

4th term = A+(4-1)d= A+3d

18th term = A+(18-1)d= A+17d

ATQ

4×(4th term ) = 18×(18th term)

4A+12d =18A+306d

4A+12d= 18A+306d

14A= -294d

A=-21d

22nd term = A+(22-1)d= A+21d

-21d+21d=0

22nd term is 0.