Answer:
Juanita will run and swim again on the same day in 15 days from today
Step-by-step explanation:
Hi
As Juanita runs every third day and nothing every fifth day. We can see that 3 and 5 are prime numbers, so they have no common factors between them.
Then we see their multiples
[tex]3=3,6,9,12,15,.....\\5=5,10,15,.....[/tex]
Therefore [tex]15[/tex] is the minimum multiple common, Juanita will run and swim again on the same day in 15 days from today, and every 15 days, so on.
