Question

How many terms are there in the AP whose first term is -8, 7^th term is 34 and sum of all the terms is 615?

• A. 12
• B. 14
• C. 16
• D. 15
• E. 17

Answer 1

The correct option is D 15

Sololution: Option (d)

First term is (a) = -8, 7^th term is (a + 6d) = 34

6d = 42

d = 7

Sum of all the terms = [2a + (n- 1)d]

615 = (-16 + (n – 1)7)

Solving we get n = 15, i.e. 15 terms are there in the A.P.