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 number of such arrangements is

Four novels can be selected from 6 novels in  6C4 ways. One dictionary can be selected from 3 dictionaries in  3C1 ways.As the dictionary selected is fixed in the middle, the remaining 4 novels can be arranged in 4! ways.∴ The required number of ways of arrangement =6C4×3C1×4!=1080