A nurse worked from 8:15 am until 11:30 am and 12:30 am until 4:15 pm. estimate the total number of hours worked

Ok so lets work it out (answer at the bottom in bold)

11:30 - 8 : 15 = 3:15 (3 hours and 1 5 minutes)

and for the next part its a little trickky cause we are going from am to pm but we can work it out

so we know it will end in 45 because it takes 30 + 30 = 1 hour and it says 4: 15 so we know we need a 15 and 15 + 30 = 45

so now we will put 45 to the side but we now instead of having 12:30 we have 1 : 00 pm and 4:00 pm

4:00 - 1 : 00 = 3 pm and now we take the 45 and add it to the 3:00 pm so 3:00 + 45 = 3:45 pm

and now we add our 2 end results

3 : 45 + 3:15 = 7 hours

The nurse worked 7 hours