<p>So, like quite a few people, I really suck at distance problems. </p>
<p>To help these people, and myself, I thought that we should make a thread dedicated solely to distance problems. Post any such problems you can, along with answer choices (assuming the question is a multiple choice question), and, of course, the answer. If you post a problem taken from a prep book (including the blue book), please include the name of the book in your post.</p>
<p>I don’t know if a lot of people will participate in this, but it could eventually become a great resource for those struggling with distance problems.</p>
<p>Both of these are taken from the Barron’s book, on page 438.</p>
<p>8. Two printing presses working together can complete a job in 2.5 hours. Working alone, press A can do the job in 10 hours. How many hours will press B take to do the job by itself?</p>
<p>A) 3<em>1/3 B) 4 C) 5 D) 6</em>1/4 E) 7*1/2</p>
<p>Answer: A) 3*1/3</p>
<p>9. Henry drove 100 miles to visit a friend. If he had driven 8 miles per hour faster than he did, he would have arrived in 5/6 of the time he actually took. How many minutes did the trip take?</p>
<p>From now on, I think I’m going to help the questioner solve the problems by himself, rather than just explain the answer.</p>
<ol>
<li><p>You know that press A can do the job in 10 hours. You also know that press A and B working together can get the job done in 2.5 hours. So press A and press B are working at the same time. Is there a way to find out how much of the job press A completed in one hour? Is there a way to find out how much of the jobb press B completed in one hour?</p></li>
<li><p>Henry drove 100 miles to visit a friend. If he had driven 8 miles per hour faster than he did, he would have arrived in a shorter amount of time. We already have a variable, distance. Should we introduce another? What should we call this variable?</p></li>
</ol>
<p>Sorry for the double post, but I noticed that the problems rockermcr posted are from Barron’s, which I know is usually harder/inaccurate in comparison to collegeboard distributed tests. I don’t usually see that many distance problems at all, from the QAS, BB and OC tests that I have done, but is it practical to believe problems of this caliber would show themselves on the test?</p>
<p>I did them both correctly, but I’m just wondering.</p>
<p>For number 8, this is how I did it.
A takes 10 hours to do the whole job, so in 2.5 hours, A does 1/4 of the job. Therefore B does 3/4 of the job. That means that B is 3 times faster than A. Since A takes 10 hours, B would take 1/3 of that time, 3 and 1/3 hours.</p>
<p>Number 9 is a little harder.
I just used a system of equations to do it.
Define x as the speed in miles per hour
Define y as the time in hours.
The time it took is distance/speed, so the two equations are:
y = 100/x
(5/6)y = 100/(x+8)</p>
<p>Solving the system of equations yields y = 5/2, which is 2.5 hours which equals 150 minutes.</p>
<p>this kind of problem is not that hard to solve if u do grubers, its actually quite simple, like shiomi said, d=rt.
i believe those 2 Qs are from barrons how to prep for the Sat lol… i rmeember those long ago…
one thing is u gotta find out the rate… 1/total hrs, thats a big hint…
have fun. ;)</p>