ive persons entered a lift cabin on the ground floor of an 8-floor house. Suppose that each of them

Question

Five persons entered a lift cabin on the ground floor of an 8-floor house. Suppose that each of them can leave the cabin independently at any floor beginning with the first. What is the total number of ways in which each of the five persons can leave the cabin at any of the 7 floors?

Answer 1

Any one of the 5 persons can leave the cabin in 7 ways independent of other.
Hence the required number of ways = 7 × 7 × 7 × 7 × 7 = 75.