Question

In an A.P., if d =−4 and a₇ = 4, then the first term 'a' is equal to ______.

Options

• 6

• 7

• 20

• 28

Answer 1

In an A.P., if d =−4 and a₇ = 4, then the first term 'a' is equal to 28.

Explanation:

d = − 4, a₇ = 4

t_n = a + (n − 1)d

a₇ = a + (7 − 1) − 4

4 = a + (−24)

4 + 24 = a

∴ a = 28.