Math question

Test Preparation SAT Preparation
1

<p>this comes from the SAT Preperation BOoklet 2005-2006</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 represents the length of that call, in minutes?</p>

<p>I tried it this way but got it wrong:
555 = x + yt
555 - x = yt
(555 - x) / y = t
Answered (A) (555 - x) / y</p>

<p>Correct answer: (C) (555 - x + y) / y</p>

<p>Could anyone explain this?</p>

2

<p>m = total # of minutes...</p>

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

3

<p>thanks! one more:
theres a picture of a triangle but its not to scale anyway. It is simply a triangle, ABC
In the figure above, AC = 6 and BC = 3. Point P lies on line segment AB between A and B such that CP is perpindicular to AB. Which of the following could be the length of CP?
(A) 2
(B) 4
(C) 5
(D) 7
(E) 8</p>

<p>the answer is (A) 2</p>

<p>i dont know how to do this at all!</p>

4

<p>Well, if you draw out triangle ABC with line CP perpendicular to AB, you will have 2 right triangles. Since triangle CPB is a right triangle with hypotenuse 3, you know that CP has to be less than 3. Since the legs of a right triangle cannot be more than the hypotenuse. So the only logical answer is 2.</p>

5

<p>wow these things are so simple, but seem so complicated! thanks soo much!</p>