Confusing Math Q.

Test Preparation SAT Preparation
1

<li>The daytime telephone rate between two cities
is 90 cents for the first 3 minutes and c cents for
each additional minute. The total charge is reduced
65 percent on calls made after 11:00 P.M. The cost,
in dollars, of a 30-minute call made at 11:15 P.M.
between these two cities is
(A) 0.35(0.90) + 27c
(B) 0.35(0.90 + 0.27c)
(C) 0.35(0.90 + 9c)
(D) 0.65(0.90 + 27c)
(E) 0.65(0.90 + 0.30c)</li>
</ol>

<p>Please tell me how you did it. thanks. :]
this is from CB’s #2 test from the Online Course.</p>

2

<p>The answer is B right?</p>

<p>I think this is the answer so I'll go ahead and explain what I did.
The call is made after 11:00 pm so the total charge will be multiplied by .35, which is the total cost reduced by 65%.
The total cost is (.9 + .27c).35</p>

<p>I think you might have gotten confused by the minutes being placed as .27, but you can just plug in numbers to get past this.
Let's say c = 10 cents per call. 27 * .1 = 2.7 and .27 * 10 = 2.7.</p>

3

<p>Yes it is b.</p>

<p>The cost is .9 for the first 3 minutes. There are 27 minutes remaining, so the cost for the remaining minutes is .27<em>c. Since it is after 11, the cost is only .35 of what it was in the day. So the total cost is .35</em>(.9 + .27c)</p>

4

<p>It's B.</p>

<p>The call lasts for 30 minutes. For the first three minutes, 0.9 dollars are charged. For the next 27 minutes, c cents or 0.01c dollars are charged per minute. So, the subtotal for the thirty minutes would be:
=> $ 0.9 + (27 x 0.01c)
=> $ 0.9 + 0.27c</p>

<p>It it then reduced by 65%, leaving only 35% of the original cost as 100-65=35.</p>

<p>So, the final cost becomes:
=> $ 35/100 x (0.90 + 0.27c)
=> $ 0.35(0.90 + 0.27c)</p>

<p>PS - Wow, I type slow. :D</p>

5

<p>First calculate cost of regular call - don't include discount:</p>

<p>.90 for first 3 min - never changes.
27 min for rest of call (30-3 = 27). (You already paid for the first 3 min, don't double charge.)</p>

<p>So, the current equation is .90 + 27c , where c is the cost per minute.</p>

<p>Now, add in the discount for late-night calls.</p>

<p>Since a 65% discount is given, you are only paying 35% of the original cost for the call (100 - 65% = 35%)</p>

<p>Put the 35% in front of the first equation to get .35(.90 + 27c)</p>

<p>The answer is B.</p>

6

<p>wow, triple post anyone?</p>

7

<p>we all decide to post 10 minutes after the OP made the thread. We like to keep people waiting dont we? To make them sweat it out.</p>

8

<p>why is it .27? that's where I got confused
I got .35(.9+27C)
when I looked, I saw .27
In the question it stated that c was already in cents, so we don't have to convert.</p>

9

<p>The answer asks for the amount in dollars. So you have to convert c to dollars. ;)</p>

10

<p>c is in cents. But we want it in dollars. 100 cents = 1 dollar. So .01 x cents = the value in dollars.</p>

11

<p>ah, ok.
thanks :D</p>

12

<p><a href="http://i34.tinypic.com/axjznk.jpg%5B/url%5D"&gt;http://i34.tinypic.com/axjznk.jpg&lt;/a>
Another question. #8</p>

13

<p><MNO + 2x + x+5 = 180 (sum of angles in triangles)
<MNO + x + y = 180 (sum of angles on a straight line)</p>

<p>Thus, 2x + x+5 = x+y
3x + 5 = x + y</p>

<p>y = 2x+5</p>

14

<p><a href="http://i37.tinypic.com/ddizh1.jpg%5B/url%5D"&gt;http://i37.tinypic.com/ddizh1.jpg&lt;/a>
what about #16?
Sorry, I don't have access to the key so I'm making sure I'm doing stuff right.</p>

15

<p>^I got a=4, because the base is a and the height is a, and
(a^2)/2 = 8</p>

16

<p>Perimeter</a> and Area of a Triangle Given its Vertices</p>

<p>Lol, you can check using this. I got an a of 4.</p>

17

<p>Anyone get the feeling that SAT math is the same stuff over and over again?</p>

18

<p><a href="http://i33.tinypic.com/1puyqh.jpg%5B/url%5D"&gt;http://i33.tinypic.com/1puyqh.jpg&lt;/a&gt;&lt;/p>

<h1>6, I got C</h1>

<p>Is there a way to get less than 2?</p>

19

<p>^nope..you need to get the solutions to these ._.</p>

20

<p>CB's online thing is bugged.
It gives me errors ._.</p>

<p><a href="http://i36.tinypic.com/imo3o1.jpg%5B/url%5D"&gt;http://i36.tinypic.com/imo3o1.jpg&lt;/a>
Would #12 be B?</p>