Question 61: Cars A and B

Algebra Level 2

Car A began a journey from a point at 9 am, traveling at 30 mph. At 10 am car B started traveling from the same point at 40 mph in the same direction as car A. At what time will car B pass car A?

Use a 24 hour clock. If your answer is 13:45, enter it as 1345.

Algebra 1 EOC Study Guide. How many can you solve correctly?


The answer is 1300.

This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try refreshing the page, (b) enabling javascript if it is disabled on your browser and, finally, (c) loading the non-javascript version of this page . We're sorry about the hassle.

1 solution

Lew Sterling Jr
Jan 26, 2015

Let after t hours the distances D1 traveled by car A

=> D1 = 30 t

Car B starts at 10 am and will therefore have spent one hour less than car A when it passes it.

After (t - 1) hours, distance D2 traveled by car B

=> D2 = 40 (t - 1)

When car B passes car A, they are at the same distance from the starting point and therefore D1 = D2

=> 30 t = 40 (t - 1)

Solve the equation for t,

=> 30 t = 40t - 40

=> 10 t = 40

=> t = 4

=> Car B passes car A at = 9 + 4 = 13 pm.

I do not understand why you would put a.m. and assume 24 hr time though. I would have assumed 1 p.m. Good question though.

Cool Math - 6 years, 4 months ago

Log in to reply

Well, in military time...1300 is 1pm.

Lew Sterling Jr - 6 years, 4 months ago

Log in to reply

Assuming it is military time, you would not put in 9.a.m. would just be 900

Cool Math - 6 years, 4 months ago

Thanks. I have updated the phrasing of the problem.

In future, if you spot any errors with a problem, you can “report” it by selecting "report problem" in the “dot dot dot” menu in the lower right corner. This will notify the problem creator who can fix the issues.

Calvin Lin Staff - 6 years ago

0 pending reports

×

Problem Loading...

Note Loading...

Set Loading...