Choose the correct choice in the following and justify :

30th term of the A.P. : 10, 7, 4, ….., is

1. 97

2. 77

3. -77

4. -87

Given,

A.P. : 10, 7, 4, …..,

First term (a) = 10 and common difference (d) = 7 - 10 = -3.

By formula,

a_n = a + (n - 1)d

Substituting values we get :

a₃₀ = 10 + (30 - 1)(-3)

= 10 + 29 × -3

= 10 - 87

= -77.

Hence, Option 3 is the correct option.