January 2008 SAT Hard Math Question HELP #18

JohnTee
Sat, 27 Jul 2013 06:09:47 +0000

^ The proportions is basically the same thing you did, except it’s safer. Especially for a question near the end of a math section. Your way is Distance / time, which is complicated because the time is not 3/4. The “time”, you meant, is the proportion between the total time over an hour. Which is what I did. If you try to teach a guy who doesn’t know how to do the problem, skipping a step won’t be the best way to teach him. Btw your post above Avg speed = (total distance) / (total time) is misleading. Total distance, 20 divided by total time, 45, gives you 0.4. So, the avg. speed is 0.4? per second? per year? Either way it’s the wrong explanation.