Question 535173
10
First I figured out what time she arrived at her appointment
Her appointment was at 11:15 and she was 15 minutes late, so she arrived at 11:30
Then, I figured out how long it took her to get there
I divided 60 by 40 because she averaged 60 km/hr and it is 40 km from her house
 60/40=1.5, which is 1 hour and 30 minutes
Then I subtracted 11:30 minus 1 1/2 hours, because that is subtracting the time she arrived by how long it took her to get there, so the answer will be what time she left the house
11.50-1.5=10
so she left her house at 10