Question

Winter Middle school must end at 3:00 pm for the buses. There needs to be 5 hours for class, 45 minutes for lunch, 10 minutes for daily announcements, 25 total minutes for changing classes, and 1/2 hour for assemblies. What time does Winter Middle School need to start in the morning?

Answer 1

Explanation:

So we'll be working backwards here,

I like to convert 3:00 pm to a 24 hour clock, which is 12+3, or 15:00.

From there, subtract 5.5 hours (for class and assemblies). 15 - 5.5 = 9.5

Next, add all of the minutes together. 45 + 10 + 25 = 80 minutes.

Now, you probably know there are 60 minutes in an hour, so we can make 80 minutes = 1 hour and 20 minutes. Subtract an hour from 9.5 now, 9.5 - 1 = 8.5

Almost there, we still have 20 minutes to account for. Now, since there are 60 minutes in an hour, we can take the ".5" from 8.5 and make it into 30 minutes (60 minutes/hour * 0.5 hours).

Finally, subtract the 20 minutes from the 30. 30 - 20 = 10.

So school has to start at 8:10. Yikes.