If 18th and 11th term of an A.P. are in the ratio 3 : 2, then its 21st and 5th terms are in the ratio

As 18^th term : 11^th term ratio is 3:2

18^th term is a + 17d and 11^th term is a + 10d

3a + 30d = 2a + 34d

a=4d…………….(1)

21^st term is a + 20d = 24d (putting value of a from (1))

And 5^th term is a + 4d= 8d (putting value of a from (1))

Ratio of 21^st term : 5^th term is

= 3:1