question_answer

Number of ways in which 7 green bottles and 8 blue bottles can be arranged in a row, if exactly 1 pair of green bottles is side by side, is (assume all bottles to be alike except for the colour)

A) 104                   

B) 284                   

C) 504       

D) 672

Correct Answer: C

Solution :

[c] After arranging 8 blue bottles; 1 gap for 2 green bottles can be selected in ways. For the remaining 5 green bottles, 5 gaps can be selected from 8 gaps in  ways. Hence, total number of ways