Problema Solution

Two cars leave City A at the same time to travel to City B. One car travels at 72 km/h and the other at 78 km/h. If the slower car arrives 20 minutes after the faster car, how far apart are City A and City B

Answer provided by our tutors

distance = speed * time


both cars travel the same distance, let 't' represent the time driven by the faster car in hours, then 't+(20/60)' represents the time drive by the slower car and we set their speed*time expressions equal to each other:


78t = 72(t+(20/60))

solving for 't' we have t=4


the faster car drove 78 km/h for 4 hours:

78*4 = 312


City A and City B are 312 km apart