question_answer

From 6 different novels and 3 different dictionaries, 4 novels and 1 dictionary are to be selected and arranged in a row on a shelf so that the dictionary is always in the middle. The number of such arrangements is: [JEE Main Online 08-04-2018]

A)  at least 500 but less than 750

B)  at least 750 but less than 1000

C)  at least 1000

D) less than 500

Correct Answer: C

Solution :

\[\text{6 }{{\text{N}}_{\text{1}}}\text{ 3D}\] \[\text{=15}\text{.3}\text{.24}\] \[\text{=45}\times \text{24}\] \[=1080\]