SAT Math Question Help

Test Preparation SAT Preparation
1

<p><a href=“http://24.media.■■■■■■■■■■/817ec192c960ac2f4a33389867bd4cc3/tumblr_mrnps4zYw51r50wtuo1_400.png[/url]”>http://24.media.■■■■■■■■■■/817ec192c960ac2f4a33389867bd4cc3/tumblr_mrnps4zYw51r50wtuo1_400.png&lt;/a&gt; </p>

<p>How do you solve this problem?
The answer is C. I would like to know the method in solving this. Thank you!</p>

2

<p>Alright, so percent change is change/original<em>100. The change=two because the 4pm data point is two lines below that of the 3pm data point, and the problem states that each line represents one foot. With this information we can set up the equation: 2/x</em>100=10. Solving this gives x=20, which is the depth at 3pm. Subtract two from that makes 18, answer choice C.</p>

3

<p>You are told that each dashed horizontal increment is 1 foot. So the difference between 3 and 4 is two feet.</p>

<p>So 2 feet is 10% of what number? (2x10=20) So at 3pm, the water is at 20 feet high. So it loses 10%, which is 2 feet, making it 20 - 2 = 18, answer C.</p>

4

<p>I used the answers to help me.
I made the equation
x-.1x= (answer choice a,b,c,d)
And I knew x had to be two more than the answer choices because in the graph it says so.
So
.9x=3 x=3.33 so is wrong cause is not 5
.9x=15 x=16.6 Wrong cause is not 17
.9x=18 x=20 right cause is two apart from 18</p>

5

<p>It’s easy!</p>

<p>Water level decreased by 2 feet from 3:00 to 4:00. Since we are told this is 10%, the question is: 2 is 10% of what number? Obviously 20. Thus, the water was 20 ft high at 3:00, and (20 - 2) = 18 ft high at 4:00.</p>

<p>The problem seems confusing because the answer choices are so big and the graph only shows six vertical units, but you have to notice the small strip at the bottom left of the graph that is wavy—it indicates that the true graph is really bigger.</p>

<p>If this last paragraph made no sense to you, just ignore it and focus on the first part.</p>

6

<p>Thanks for the solutions!
I have some more questions I need help with, if I can kindly get more assistance. Thank you in advance!</p>

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7

<p>Bump bump.</p>

8

<ol>
<li>Not entirely sure about this one, but I’ll try to explain.
There are 7 spots. It should look like this:
2, _ , _ , 6, _ , _ , 20 when arranged in order. Since 3 repeated the most, the 2 spots in between 2 and 6 are 3s.
2, 3, 3, 6, _ , _ , 20</li>
</ol>

<p>The average will look something like this:
(2+3+3+6+20+x+y)/7, x and y being 2 different numbers that are greater than 6 but less than 20. It then looks like this:
(34+x+y)/7 = Avg.
Now for the average to equal 7, x and y have to add up to 15, which means x could be 7 and y could be 8. So the average could be 7.
For the average to equal 8.5, x and y have to add up to 25.5, which means x could be 12 and y could be 13.5, which also works.
For the average to equal 10, x and y have to add up to 36, which means x could be 17 and y could be 19. </p>

<p>That means the answer is E as all choices work. I hope I’ve worked it out properly, please correct me if I’m wrong. </p>

<ol>
<li><p>In order to get this one, you should know that the radius is half of the diameter. Since the sphere touches all 6 sides and is contained within the cube, the diameter is equal to one side of the cube. That simply means we cube the diameter in order to find the volume of the cube = (2r)^3 = 8r^3</p></li>
<li><p>For this, you have to set up an equation to solve the problem. I came up with this:
Price at n year = $10 + 2(n - 1990). So when it is 1991, the price would be 10 + 2(1991 - 1990) = 10+2 = 12.
Now simply set the price to 100 and solve for the year.
100 = 10 + 2(n - 1990); you should get that n = 2035. </p></li>
<li><p>The answer is E, 1994. Simply look at the values and you’ll see that the value of School B population in 1994 is 1600 and the School A population is 800, therefore the ratio is 2:1, which is the greatest on the graph. </p></li>
<li><p>Isolate y and you’ll get the equation: y = -(tx/12) - (1/4)
Since the slope is equal to -10, -tx/12 has to equal -10.
Set that up as an equation and you’ll get that t = 120. </p></li>
</ol>

<p>I may have gotten a few wrong, please correct me if I did! Hope it helps a bit.</p>