13. Two taps are turned on together. One tap drips once every three
    seconds and the other tap drips once every five seconds. How many
    times in the next twenty four hours will they drip at the same time?

In a 24-hour period, there are 86,400 seconds (24 hours × 60 minutes × 60 seconds). The first tap drips once every 3 seconds, and the second tap drips once every 5 seconds. To find out when both taps drip at the same time, we need to determine the least common multiple (LCM) of these two intervals. The LCM of 3 and 5 is 15 seconds. So, they will both drip together every 15 seconds.

Now, divide the total seconds in a day by the time interval of 15 seconds:
86,400 seconds ÷ 15 seconds = 5,760.

Therefore, the two taps will drip together 5,760 times in the next 24 hours!