Question

If 5th term of an HP is 1/45 and the 11th terms is 1/69, then its 16th terms will be

(A) 1/89

(B) 1/85

(C) 1/80

(D) 1/79

Answer 1

Correct option**(A) 1/89**

Here 5th term of the corresponding AP is

a + 4d = 45 ....(1)

and 11th term of the corresponding AP is

a + 10d = 69 .....(2)

From Eqs. (1) and (2), we get a d = 29,d = 4. Therefore, 6th term of the corresponding AP is

a + d = 15 = 29 + 15 x 4 = 89

Hence, 16th term of the HP is 1/89