imc

Question

Angelina drove at an average rate of 80 kmh and then stopped 20 minutes for gas. After the stop, she drove at an average rate of 100 kmh. Altogether she drove 250 km in a total trip time of 3 hours including the stop. Which equation could be used to solve for the time t in hours that she drove before her stop?

Accepted Answer

The answer is A because she drove at 80 kmh for t hours (the amount of time before the stop), and 100 kmh for 83-t because she wasn't driving for 20 minutes, or 13 hours. Multiplying by t gives the total distance, which is 250 km. Therefore, the answer is 80t+100(83-t)=250 80t+100(83-t)=250