Four persons enter a lift on the ground floor of an \(8\)-floor building(excluding the ground floor). Each person is equ

[Vincen]

Four persons enter a lift on the ground floor of an \(8\)-floor building(excluding the ground floor). Each person is equally likely to leave the lift on any floor except the ground floor. What is the probability of all the persons leaving the lift on different floors?

A. \(\dfrac{105}{512}\)

B. \(\dfrac{105}{256}\)

C. \(\dfrac{112}{243}\)

D. \(\dfrac{1560}{2147}\)

E. \(\dfrac78\)

Answer: B

Source: e-GMAT