Question

From 6 different novels and 3 different dictionaries 4 novels and , 1 dictionary are to be selected and arranged in a row on the shelf so that the dictionary is always in the middle. Then the no, of such arrangements is _______

(a) Less then 500 

(b) At least 500 but less then 750 

(c) At least 750 but less then 1000

(d) At least 1000

Answer 1

Correct option: (d) At least 1000

Explanation:

N = Novel and D = Dictionary, NNDNN

selection of D = 3

arrangement of NNNN = ⁶P₄ = 360

∴ Total arrangements = 3 x 360 = 1080