Two cars start from a certain place and travel in opposite direction one goes to 55 km per hour how many hours will they be 135 km apart
Answers
Answer:
In this case - we could just as well write the problem as “how long until the combined mileage travelled by both cars equals 135 km?”
We can write this reworded problem in an equation like this:
x[hours](55[km/hour]+35[km/hour])=135[km]
which reduces to:
x[hours](90[km/hour])=135km
Note here how the units are equal on both sides if we were to cancel out the terms - we’d be left with [km]=[km] . But we don’t want to cancel units yet; we’d be left with an x with no units, which won’t do. For now, it’s a good smell test to see we’re on the right track.
Solve for x by dividing each side by 90[km/hour] :
x[hours]=135[km]/(90[km/hour])
x[hours]=1.5[hours]
Our units match, and we have a complete answer: “It takes 1.5 hours for both cars to travel a combined distance of 135 km.”