GRE Question of the day – 15/10/16:
Numerical Entry question:
Jack and four friends go to a game. In how many ways can they be seated in 5 consecutive seats, if Jack has to sit between any two of his friends?
The seating can be
_ J_ _ _
_ _ J _ _
_ _ _ J _
J : Jack
_ : Seat
In each of the above arrangement there are 4! ways for the friends to sit. As there will be 4 ways to fill the first empty, 3 for next empty, 2 to next empty and 1 for the last remaining. Hence, total will be 3 x 4! = 72