Question

If 7 times the 7 th term of an

a.P. Is equal to 11 times the 11th term of the

a.P., find its 18th term

Answer 1

Answer:

a=first term

d=common difference

GIVEN-

7(7th term)=11(11th term)

7(a+6d)=11(a+10d)

7a+42d=11a+110d

11a-7a=42d-110d

4a=-68d

a=-17d........equation 1

18th term=a+17d

=-17d+17d (from equation1)

=0

18th term=0.