Question

find the term of A.P. 9, 12, 15, 18,... which is 39 more than its 36th term

Answer 1

Solution

→ d = Second Term - First Term

→ d = 12 - 9

→ d = 3

→ 36th term = a + 35d

→ 36th term = 9 + 35(3)

→ 36th term = 9 + 105

→ 36th term = 114

Now we have to find nth term with value 39 more than 36th term.

→ 39 + 36th term = a + (n - 1)d

→ 39 + 114 = 9 + (n - 1)3

→ 144 = (n - 1)3

→ 48 + 1 = n

→ 49 = n

Hence 49th term is correct answer.