Question

Choose the correct answer in each of the following questions:

An AP 5, 12, 19, ... has 50 terms. Its last term is [CBSE 2015]

(a) 343 (b) 353 (c) 348 (d) 362

Answer 1

The given AP is 5, 12, 19, ... .

Here, a = 5, d = 12 − 5 = 7 and n = 50

Since there are 50 terms in the AP, so the last term of the AP is a₅₀.

$$\begin{gathered} a_{50}=5+\left(50-1\right)\times 7\left[a_n=a+\left(n-1\right)d\right] \\ =5+343 \\ =348 \end{gathered}$$

Thus, the last term of the AP is 348.

Hence, the correct answer is option C.