How would you approach this math problem?

Test Preparation SAT Preparation
1

<p>What do you think is the quickest and easiest way to approach this problem:</p>

<p>A telephone company charges x cents for the first minute of a call and charges for any additional time at a rate of y cents per minute. If a certain call costs $5.55 and lasts more than 1 minute, which of the following expressions represnts the length of that call, in minutes?</p>

<p>A. (555 - x)/ y
B. (555 + x - y)/ y
C. (555 - x + y)/ y
D. (555 - x - y)/y
E. 555 / (x + y) </p>

<p>I used parenthesis to avoid confusions.</p>

2

<p>I don't have time to figure it out now, but I would plug in numbers! You already have x(5.55), and then you have Y. Let's say that the call is one minute extra and they charge $1 per extra minute. In the end, it turns out to be $6.55, and then you just plug in X and Y into each one of those until you get 6.55.</p>

3

<p>I used to get confused with these types of problems but life can be a whole lot easier if you plug in your own values.
Say for the first minute x, you pay 55 cents, and for each additional minute y, you pay 50 cents. Your total is 550 cents.</p>

<p>So your equations is 55 + 50n = 550, n being number of additional minutes
Solve for n = 10. So your total minutes are 11 counting the first minute costing 55 cents.</p>

<p>Now substitute x =55 and y = 50 in the answer choices to see what gets you 11. It turns out the answer is C.</p>

<p>Took about a minute.</p>

4

<p>I agree with akamed (the soon to be SAT tutor). This is a typical "plug in some values" problem.</p>

5

<p>Or you could just set up an equation based on the info you're given:</p>

<p>x + y(m - 1) = 555 where m = minutes</p>

<p>y(m - 1) = 555 - x</p>

<p>m - 1 = (555 - x)/y</p>

<p>m = (555 - x)/y + 1</p>

<p>m = (555 - x)/y + y/y</p>

<p>m = (555 - x + y)/y</p>

<p>As other people have said, the answer is C.</p>

6

<p>I'd do what bts7390 did.</p>

7

<p>Celita's way is good, but would mine above work too? I don't have time to think about advanced things with limited time, just my current knowledge(which is still pretty good). Princeton Review saved me by telling me to plug in. Like akahmed said, plugging in is the easiest thing in the world to get around these problems. If the SAT wasn't multiple choice, plugging in wouldn't be possible and you'd have to study math extensively. </p>

<p>The Math section is ridiculously easy though in many questions(not just easy). You can sometimes guess answers by knowing it can't be over X and and under Y and it must be in between. On Geometry answers where hte figure is drawn to scale, you can guess at it and rule out the hard ones.</p>