Question

In an AP, if d = –4, n = 7, an = 4, then a is ______.

Options

• 6

• 7

• 20

• 28

Answer 1

In an AP, if d = –4, n = 7, an = 4, then a is 28.

Explanation:

We know that n^th term of an AP is

a_{n =} a + (n – 1)d

where,

a = first term

a_n is nth term

d is the common difference

4 = a + (7 – 1)(– 4)

4 = a – 24

a = 24 + 4 = 28