Craig is training for a race. He bikes every 2 days and swims every 3 days. If he biked and swam today, how many days will pass before he bikes and swims on the same day again, the least common multiple of the numbers of days?

Question

Multiples of 2: 2, 4, 6, 8, 10, 12, . . .
Multiples of 3: 3, 6, 9, 12, 15, 18, . . .

2 days
3 days
6 days
12 days

Answer 1

To find the least common multiple (LCM) of the biking interval (2 days) and the swimming interval (3 days), we can list the multiples of each:

• Multiples of 2: 2, 4, 6, 8, 10, 12, ...
• Multiples of 3: 3, 6, 9, 12, ...

The smallest common multiple is 6.

Therefore, the least number of days that will pass before Craig bikes and swims on the same day again is 6 days.