Question

HOW DO YOU DO THIS??????????

Answer 1

from 9:00 am to 9:00pm, that's a total of 12 hours, 
so 12 of the 20 hours are charged at a rate of 0.25 dollar per hour, and the other 8 hours (20-12=8) are charged at a rate of $0.06 per hour.
the answer is b. 
it should be 0.06 though, not 0.6