A couple of math ACT questions

Test Preparation ACT Preparation
1

<p>Okay, I have 2 questions about some classic elementary problems that the ACT loves to ask.</p>

<ol>
<li><p>For the questions that ask how many diagonals can be drawn in...(this shape), is there a way to figure it out without drawing in lines and counting?</p></li>
<li><p>I never learned how to do the problems that were structured like this:
Diane works at a greeting card store and can stack 50 cards per hour.
John works at the same store and can stack 24 cards per hour.</p></li>
</ol>

<p>How many cards can they stack if they work together in one hour?</p>

<p>If anyone could give me advice, I would greatly appreciate it :) .</p>

2

<p>here is a simple formula for your first question
number of diagonals of polygon = n(n-3)/2
n is the number of vertices</p>

<p>2) diane can stack 50 cards per hour so this converts into 50x where x is the number of hours
john can stack 24 cards per hour so this converts into 24x where x is also the number of hours
since they are working together, you add 50x + 24x = y
where y is the total number of cards they can stack up in x hours
since you asked 1 hour just plug in 1 and your done, y=74</p>

3

<p>Not if they both make them separately, I’m saying if they work together with each other as a single unit.</p>

4

<p>JDE, making them work separately and then adding is the same as making them work together.</p>

5

<p>I think what JDE really is asking is how long would it take them to stack 100 cards, because this is a little more tricky. If not, then WLsilver is correct</p>

6

<p>If Computer A takes 4 hours to complete the task, and Computer B takes 2 Hours, how long will it take if they work together?</p>

7

<p>^ 80 minutes.</p>

8

<p>^He’s asking for the method, not just the answer. </p>

<p>For these kinds of questions, just put both rates as the denominators of two fractions that will add up to your answer, like:</p>

<p>1/240 + 1/120 = 1/X</p>

9

<p>^ How do you know? He never said to explain the answer.</p>

10

<p>I have a very specific math question that looks eerily simple yet I cannot conquer it. I would really appreciate some sketchy 1:30am help from ANYONE! I saw the answer online but I just cannot reach it. I’ve tried every combination possible. Take a look at the link and tell me if you have any better luck. </p>

<p><a href=“http://i55.■■■■■■■.com/35cla2u.jpg[/url]”>http://i55.■■■■■■■.com/35cla2u.jpg&lt;/a&gt;&lt;/p&gt;

11

<p>1/2bh is an awnser. The base is 4 (notice the x coordinates of 5 and 1) and the higheigt is given to you. You probably though the base was three like me in the begining</p>

12

<p>^^
Base = 4
Height = 2</p>

<p>.5(4)(2)=4
A</p>

13

<p>Thanks guys!</p>

14

<p>4 is right.</p>