In a permutation, the sequence is important. For combinations, the sequence is not important.

Clues are often provided by the nature of the question. For example, when dealing cards, the order in which the cards are dealt or received is usually unimportant. However, when dealing with locks or seating arrangements, sequence often is important.

Permutation question:

How many ways can the members of a 5-member committee be seated in a row on the dais?

Combination question:

What is the probability that 3, 4, 5 and two other numbers will be drawn from numbers 1-47 in a lottery?

Clues are often provided by the nature of the question. For example, when dealing cards, the order in which the cards are dealt or received is usually unimportant. However, when dealing with locks or seating arrangements, sequence often is important.

Permutation question:

How many ways can the members of a 5-member committee be seated in a row on the dais?

Combination question:

What is the probability that 3, 4, 5 and two other numbers will be drawn from numbers 1-47 in a lottery?