Question

The 4th term from the end of the A.P −8, −5, −2, … ,49 is

(A) 37

(B) 40

(C) 1

(D) 43

Answer 1

Correct option is (B) 40

Explanation: 

Here, a = -8

d = -5 - (-8) = 3

l = 49

a_n = a + (n - 1) d

49 = - 8 + (n - 1) 3

49 + 8 = (n - 1) 3

57 = (n - 1) 3

n - 1  = 57/3

n = 19 + 1

n = 20

The 4th term from the end is equivalent to the (20−4+1)=17th term from the start.

a₁₇ = a + (n - 1) d

a₁₇ = -8 + (17 - 1) 3

a₁₇ = -8 + 48

a₁₇ = 40

Thus, the 4th term from the end of the A.P. is 40.