Math SAT questions (Real SAT Q's) (Need Help)

<p>Here are a couple questions i got wrong on a previous SAT and i was wondering if someone could help me. Thanks!</p>

<p>Question 16:
<a href="http://i770.photobucket.com/albums/xx344/Black-And-Proud/A05761A9-B959-4C30-977E-321F8943726A-2454-000000CCE2F71710_zpsc0110a4b.jpg%5B/url%5D"&gt;http://i770.photobucket.com/albums/xx344/Black-And-Proud/A05761A9-B959-4C30-977E-321F8943726A-2454-000000CCE2F71710_zpsc0110a4b.jpg&lt;/a&gt;&lt;/p>

<p>Question 14:
<a href="http://i770.photobucket.com/albums/xx344/Black-And-Proud/5DE5CECA-CDB9-4E4F-9F0A-B2CB9BD5A083-2454-000000CD04385332_zps0b882e5c.jpg%5B/url%5D"&gt;http://i770.photobucket.com/albums/xx344/Black-And-Proud/5DE5CECA-CDB9-4E4F-9F0A-B2CB9BD5A083-2454-000000CD04385332_zps0b882e5c.jpg&lt;/a&gt;&lt;/p>

<p>Question 17:
<a href="http://i770.photobucket.com/albums/xx344/Black-And-Proud/F24B6E64-4F91-4706-997B-E33D3AA92693-2454-000000CDD3BB8353_zps92e4ce93.jpg%5B/url%5D"&gt;http://i770.photobucket.com/albums/xx344/Black-And-Proud/F24B6E64-4F91-4706-997B-E33D3AA92693-2454-000000CDD3BB8353_zps92e4ce93.jpg&lt;/a&gt;&lt;/p>

<p>Question 19:
<a href="http://i770.photobucket.com/albums/xx344/Black-And-Proud/7058AA7D-6221-4062-BBB4-1394975C38C7-2454-000000CDE98A941D_zps15578608.jpg%5B/url%5D"&gt;http://i770.photobucket.com/albums/xx344/Black-And-Proud/7058AA7D-6221-4062-BBB4-1394975C38C7-2454-000000CDE98A941D_zps15578608.jpg&lt;/a&gt;&lt;/p>

<p>Question 20:
<a href="http://i770.photobucket.com/albums/xx344/Black-And-Proud/D379E32E-9FC0-4F5F-99AB-EFCE15ECADCC-2454-000000CDF38DA2D4_zpsea935962.jpg%5B/url%5D"&gt;http://i770.photobucket.com/albums/xx344/Black-And-Proud/D379E32E-9FC0-4F5F-99AB-EFCE15ECADCC-2454-000000CDF38DA2D4_zpsea935962.jpg&lt;/a&gt;&lt;/p>

<p>Thanks a lot!</p>

<p>do you know which year/month this SAT test is from? or the official sat study guide source.</p>

<p>I’m sorry for my very detailed style. ^.^ </p>

<ol>
<li><p>You are asked to tell what happens to the function between the points a and b. Look at the function and see that it is an arc. It can’t be a or b because from a to 0 the function is decreasing and from 0 to b, it is increasing. It can’t be d because there are no x intercepts in that interval and can’t be e because there is only one y intercept at 0. The answer is C.</p></li>
<li><p>Since the sides are parallel, it means both triangles have same angles and so they are similar. Use proportion of corresponding sides. AB to DE and AC to DF. AB/5=9/6
AB=7.5</p></li>
<li><p>Start by translating the first sentence into the equation. V=Ab<em>h
Find the base area. The base is an equilateral triangle so all sides are 10 and all angles are 60. Draw a vertical line from the vertice to the base and you have a 30-60-90 triangle. Find the height of this triangle using Pythagorean theorem. 5²+h²=10²
h²= 75
h=5√3
So the area of the base is (5√3</em>10)/2= 25√3</p></li>
</ol>

<p>Back to our equation V= 25√3*8=200√3
so the answer is B</p>

<ol>
<li>Mark the whole time as T.
You’ll need formula distance=speed*time. You have to find distance downhill/hole distance</li>
</ol>

<p>Downhill: t=2/5T, s=4 miles/h, so the distance is 2/5T * 4= 8/5T</p>

<p>Uhill: t=3/5T, s=2 miles/h, the distance is 3/5T * 2 = 6/5T</p>

<p>whole distance = 8/5T + 6/5T = 14/5T</p>

<p>so the fraction is (8/5T)/(14/5T)= 4/7, the answer is A.</p>

<ol>
<li>Start by marking the radius of all circles. First circle will have radius r, second 1/2r, third 1/3r.</li>
</ol>

<p>AI + A II + A III = π
A= πr²
πr²+π(1/2r)²+π(1/3r)²=π
After solving the equation you get r=6/7, so it’s C</p>

<p>Quick tip, for Q 17 you can just memorise that the area of an equilateral triangle of side a is (√3<em>a^2)/4. Therefore area of the figure is (√3 * 100</em>8)/4 = 200√3</p>

<p>And for 19 you can just assume that he travelled for 1 hour. That doesn’t really change anything, just for simplicity sake.</p>