Question

Choose the correct answer in each of the following questions:

The next term of the AP $\sqrt{7},\sqrt{28},\sqrt{63},...$ is [CBSE 2014]

(a) $\sqrt{70}$ (a) $\sqrt{84}$ (a) $\sqrt{98}$ (d) $\sqrt{112}$

Answer 1

The given terms of the AP can be written as $\sqrt{7},\sqrt{4\times 7},\sqrt{9\times 7},...$ i.e. $\sqrt{7},2\sqrt{7},3\sqrt{7},...$ .

∴ Next term = $4\sqrt{7}=\sqrt{16\times 7}=\sqrt{112}$

Hence, the correct answer is option D.