<p>I'm horrible at it. It's my biggest weakness in the math section, and no matter how many I do or how many explanations I read, I still don't get it...</p>
<p>For example, for today's daily SAT question of the day:</p>
<p>The c cars in a car service use a total of g gallons of gasoline per week. If each of the cars uses the same amount of gasoline, then, at this rate, which of the following represents the number of gallons used by 5 of the cars in 2 weeks?</p>
<p>A. 10cg<br>
B. 2g/5c<br>
C. 5g/2c<br>
D. g/10c
E. 10g/c</p>
<p>Here's the link to the question, the answer is E--> The</a> Official SAT Question of the Day </p>
<p>But the problem is, I don't get the explanation. Why does g/c signify the amount that each car uses per week? </p>
<p>Also, is there a website I can go to for more help on these type of questions?</p>
<p>Lol. I got this one wrong too. I’m glad that someone posted it. Please note the abnormally low percentage of people who got it right.</p>
<p>Basically, the g/c get’s the price of one car because the g gallons of gas is distributed equally among the different cars for each week, which is c. Next, we were told that there were 5 cars. So, we multiple that price that we got for the one week of gas for one car by the number of cars, which is 5. Then, since they want it for 2 weeks and we had everything for 1 week, we multiple our 5g/c by 2 and get 10g/c. Not to bad once you think about it.</p>
<p>Gruber has a good guide for questions like this buried in one of his books. Chung also has some scattered throughout that are more difficult than even this (believe it or not).</p>
<p>OOHHHHHH I get it! Your explanation makes a lot more sense xD </p>
<p>And thanks for the book suggestions!</p>
<p>If you know that algebra is a weak spot, then this problem is begging for you to replace the variables with numbers. You definitely want to learn this trick:</p>
<p>“The c cars in a car service use a total of g gallons of gasoline per week.” </p>
<p>Let’s just make c=10 and g=200 …nice easy numbers and it means that each car uses 20 gallons per week.</p>
<p>“If each of the cars uses the same amount of gasoline, then, at this rate, which of the following represents the number of gallons used by 5 of the cars in 2 weeks?”</p>
<p>Well, with our numbers, a car uses 20 gallons per week, so five cars use 100 per week and in 2 weeks that would be 200 gallons.</p>
<p>Now, we put OUR numbers (c=10 and g=200) into THEIR answers…which one comes out to 200?</p>
<p>A. 10cg
B. 2g/5c
C. 5g/2c
D. g/10c
E. 10g/c</p>
<p>Try it and see…</p>
<p>BTW, if two answers match yours, make a new set of #s and recheck.</p>
<p>There is no doubt that this is LONGER than the algebraic way, but it is also easier, and you say that you have trouble with these…</p>
<p>What you did is more universal pckeller. I use that method when I can’t do it through logic. Does take longer though, but sometimes you need to use it!</p>