In how many ways can 5 balls of different colours be arranged in a row?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 120
Balls of different colours are all distinct, so every order in the row is a different arrangement. The number of arrangements of n distinct objects in a row is n!: the first place can be filled in n ways, the next in \(n-1\) ways, and so on.
Arrangements \(=5!=5\times4\times3\times2\times1=120\)