<p>I took the october sat. on some math questions, they were cylinder heavy</p>
<p>i went on sparknotes and they said the only thing you have to know about cylinders is just their volume. but i believe in that sat they asked questions about area/surface area on cylinders which i wasnt prepared for</p>
<p>what new things on the october/november sat on math that popped up? or things that showed up consistently between the two SATs if anyone remembers?</p>
<p>I don’t think surface area of cylinders is novel. I don’t mean to sound condescending but it’s pretty basic geometry.</p>
<p>The type of SAT questions on cylinders I have seen so far in the official tests are:</p>
<p>1) Given the circumference of the base(say 8 pi), and volume of 48pi. What is the total surface area of the cylinder(the curved surface and the two circular bases)? </p>
<p>2) Find the length of the line segment that connects the center of one base of the cylinder to a point on the circumference of the other base. The diameter is 6, and height is 4. </p>
<p>3) What is the volume of the largest rectangular solid that can fit inside a cylinder of radius r and height h? </p>
<p>4) What is the least volume of a rectangular solid that can be used to contain a cylinder of radius r, and height h?</p>
<p>5) What is the length of the longest rod that can be placed inside a cylinder of radius 10 cm and height of 15 cm? </p>
<p>You should definitely be able to answer these questions. </p>
<p>cheers,
Dabral</p>
<p>In reference to the above questions,
1 80 Pi
2 5
Could you please help with the remaing 3 questions.Thanks!</p>
<p>Neverend, Sparknotes is not the best resource for test preparation, as they don’t often update their information. The best resource is to research actual exams to see what has been tested. You can use that information to safely assume that you will be tested on 99% of the information you encounter on real practice tests.</p>
<p>SATQuantam, I’m curious as to where you found questions like 3 and 4 on official practice exams. They are optimization problems, which I assume would be confusing for many students. </p>
<p>3) What is the volume of the largest rectangular solid that can fit inside a cylinder of radius r and height h? </p>
<p>Largest rectangular solid would be a box that has a square base. Basically you are trying to fit a square inside a circle with radius r. The square would have a diagonal of 2r, which means that the square has a side of length sqrt(2)r.</p>
<p>Volume would then be sqrt(2)r * sqrt(2)r * h = 2(r^2)h</p>
<p>4) What is the least volume of a rectangular solid that can be used to contain a cylinder of radius r, and height h?</p>
<p>This is just like question 3, except this time you are putting a circle of radius r INSIDE a square. The square is the shape that will allow you optimization, in these types of problem.</p>
<p>If the circle has radius r in this question, the square base will have a side of length 2r.</p>
<p>Volume = 2r * 2r * h = 4(r^2)h</p>
<p>5) What is the length of the longest rod that can be placed inside a cylinder of radius 10 cm and height of 15 cm?</p>
<p>The longest rod that can be placed inside a cylinder would lie slanted inside a cylinder. It would touch opposite ends of the bases, which means the horizontal distance of the ends of the rod would be equal to the diameter of the base of the cylinder (i.e., 20cm). The vertical distance that the rod would have is equal to the height of the cylinder = 15cm.</p>
<p>Then this question becomes a good ol’ Pythagorean theorem question.</p>
<p>If you are familiar with your triples,
15^2 + 20^2 = 25^2</p>
<p>25cm.</p>
<p>summer69,</p>
<p>answer to the first one is 56pi, the second one is indeed 5. </p>
<p>i will give you hints for the remaining three questions. it is best that you spend a little bit more time thinking about how to solve these.</p>
<p>3) think about sliding a rectangular solid through the circular face of the cylinder, we know the height of the solid would be the same as the height of the cylinder. can you think about what shape should the cross section of the solid should be to cover the largest portion of the circular face of the cylinder?</p>
<p>4) this is similar to #3, but now we have to encase the cylinder with a rectangular solid. the length of the solid is the same as the height of the cylinder. what should be the cross section of this rectangular solid, and how does it relate to the diameter of the circle?</p>
<p>5) again try to position the rod inside the cylinder in different ways. we know that if we place the rod vertically the length of the rod would be identical to the height of the cylinder, 15 cm. but can we position it in some other way? think about toothbrush in a cup holder. </p>
<p>afterwards do this official sat problem discussed here:
<a href=“http://talk.collegeconfidential.com/sat-preparation/1039532-can-someone-help-me-math-problem.html[/url]”>http://talk.collegeconfidential.com/sat-preparation/1039532-can-someone-help-me-math-problem.html</a></p>
<p>cheers,
dabral</p>
<p>preply,</p>
<h1>4 is from one of the SAT Official Question and Answer Services Test, i don’t recall which year and month, let me see if i can find the exact reference. i wrote #3, because if they can ask #4, then they can ask #3 as well.</h1>
<h1>5 is based on the official sat question that is linked here. i believe it is in the collegeboard’s online sat course.</h1>
<p><a href=“http://talk.collegeconfidential.com/sat-preparation/1039532-can-someone-help-me-math-problem.html[/url]”>http://talk.collegeconfidential.com/sat-preparation/1039532-can-someone-help-me-math-problem.html</a></p>
<h1>2 is also based on an official sat question. that question is discussed in this forum here:</h1>
<p><a href=“http://talk.collegeconfidential.com/sat-preparation/1204122-sat-math-questions-help-please.html?highlight=cylinder+base+of+circumference[/url]”>http://talk.collegeconfidential.com/sat-preparation/1204122-sat-math-questions-help-please.html?highlight=cylinder+base+of+circumference</a></p>
<p>cheers,
dabral</p>
<p>here is a question that pretty much summarizes the cylinder concept tested in the october sat. this is not the official question, i wrote this one, it is different enough that there is no copyright issue as far as collegeboard is concerned. </p>
<p>a solid cylinder of radius 3 is placed vertically inside a hollow cylindrical can of inside radius 9. the height of the solid cylinder and hollow can are identical. what fraction of the volume of the cylindrical can is unoccupied?</p>
<p>Thanks for your replies. I figured out questions 1,2,5 but am still having a hard time with question 3 and 4.Could you please help with these again?Thanks for you help again.</p>
<p>Try drawing pictures to help. Then, look at my explanations again.</p>
<p>Thanks guys!</p>
<p>With sparknotes, I got a 550 on math on the october SAT.</p>
<p>Unfortunately, i have not studied anything else and the sat is tomorrow. So im officially screwed. Will do more last minute research about cylinders</p>
<p>sparknotes covers some basic stuff but i checked the blue book math questions and half the questions I can’t do by instinct. I’m screwed. Luckily I was able to get 550 last time with sparknotes preparation so maybe shoot high on critical reading and writing will balance out that medicore score</p>