Question

The 4^th term from the end of the AP: –11, –8, –5, ..., 49 is
(a) 37
(b) 40
(c) 43
(d) 58

Answer 1

The given A.P. is: –11, –8, –5, ..., 49

Rearranging the terms from last to first, we get
49, 46, 43, ..... –11

First term = a = 49
Common difference = d = 46 – 49
= –3

The fourth term is:
$$\begin{gathered} a_4=a+\left(4-1\right)d \\ =49+3\left(-3\right) \\ =49-9 \\ =40 \end{gathered}$$

Therefore, the 4^th term from the end of the AP: –11, –8, –5, ..., 49 is 40.

​Hence, the correct option is (b).