1,001 questions about the ASTB (post your scores & ask your questions here!)

[Brand0034]

Does the math portion have binomial combination? "Kyles Math section" has a worksheet with them and that seems way too complex for no calculator.
For example a question:
A jar contains ten black buttons and six brown buttons. If nine buttons are picked at random, what is the probability that exactly five of them are black?
To solve:
9C5(5/8)^5(3/8)^4
->(9!/5!4!)(5^5)(3^4)/(8^9)

That would take forever to actually multiply out by hand and no math courses even expect you to do that without calculator. Even beyond calculus where we couldn't use a calculator, these problems would never be asked.

Are the questions actually this long or are they more along the lines of basic dependent/independent probability?
i.e. "If there are 9 marbles, 3 blue, 3 red, 3 green, what are the chances of selecting 3 blue in a row without returning the marbles?"

 

[njrecc]

Does the math portion have binomial combination? "Kyles Math section" has a worksheet with them and that seems way too complex for no calculator.
For example a question:
A jar contains ten black buttons and six brown buttons. If nine buttons are picked at random, what is the probability that exactly five of them are black?
To solve:
9C5(5/8)^5(3/8)^4
->(9!/5!4!)(5^5)(3^4)/(8^9)

That would take forever to actually multiply out by hand and no math courses even expect you to do that without calculator. Even beyond calculus where we couldn't use a calculator, these problems would never be asked.

Are the questions actually this long or are they more along the lines of basic dependent/independent probability?
i.e. "If there are 9 marbles, 3 blue, 3 red, 3 green, what are the chances of selecting 3 blue in a row without returning the marbles?"

I experienced nothing that would take that long to work. I read a comment on this thread saying he had a question that took him like 4 minutes. I doubt that they would have a question like that that would take so long to compute since they know you don't have a calculator. If I had received that question I probably would've guessed and moved on instead of spending that much time.

 

[JbtheArchitect]

I experienced nothing that would take that long to work. I read a comment on this thread saying he had a question that took him like 4 minutes. I doubt that they would have a question like that that would take so long to compute since they know you don't have a calculator. If I had received that question I probably would've guessed and moved on instead of spending that much time.

basic independent and dependent probability I understand some of the problems are bit complex but from the things I've read about the math portion lead me to believe it could get very challenging. That is why i wanted to challenge myself with difficult problems. A lot of the math in the practice sets i made are from digging through the forum as well.

 

[SHART]

Hey everyone, can someone explain the answers to the attached. At first I was getting it, or so I thought. Now I'm just lost in the storm and I want to get proficient before my test on thursday. Thank you in advance.

 

[sskanchiraju]

Hey everyone, can someone explain the answers to the attached. At first I was getting it, or so I thought. Now I'm just lost in the storm and I want to get proficient before my test on thursday. Thank you in advance.

Using the first one as an example, the heading is southwest so if you were to look that way the A lot would be the one to your right, and the D lot would be the one to your left. In the case of the first card, South is to the left of Southwest so it would be the D lot.

 

[SHART]

Using the first one as an example, the heading is southwest so if you were to look that way the A lot would be the one to your right, and the D lot would be the one to your left. In the case of the first card, South is to the left of Southwest so it would be the D lot.

So what I need to do is in a sense spin the orientation of the map to act as if the arrow is pointing north a find the parking lot that way? So for the first one rotate the SW arrow north and thus south being to the left?

 

[sskanchiraju]

So what I need to do is in a sense spin the orientation of the map to act as if the arrow is pointing north a find the parking lot that way? So for the first one rotate the SW arrow north and thus south being to the left?

Pretty much. If it's one of the main four cardinal directions, the A lot is the heading itself. If it's one of the diagonals, then the A lot is to the right while the D lot is to the left. There is a video floating around about the compass trick that is super helpful where you draw out a compass and rotate it based on the question. I'm taking the exam on Wednesday so I can't vouch for it yet, but personally I used the video to understand the section itself but find it easier just to visualize spinning the orientation in my head.

 

[Brand0034]

Can someone verify the Barron's book has this wrong? They used the opposite formula for each problem.
Number 15 the answer should be 2 because it has twice the area.
Number 12 should be 4 because it's twice the diameter which would equal 4x the area.

 

[jlebsock]

I've been noticing some information with some faulty facts when it comes to "self-made" practice tests and notes posted on here. Don't get me wrong they are still an excellent source of information but for example in the "OAR Mechanical Comprehension" study guide ive seen floating around this forum there are a few answers that are wrong.

-Example: #67 "how is lift generated from airfoils?" and the answer on the guide is the low pressure underneath the wing is what causes lift. The correct answer would be the low pressure ABOVE the wing is the major source of lift. Its sort of a vacuum principle. Just be careful and if something seems unsure to you from these other attachments just double check from a credible source.

 

[Brand0034]

This is from a certified study book which I thought was strange. Not just a personal study guide. I’ve found multiple mistakes in this book alone. Just makes me second guess myself sometimes lol.

 

[jlebsock]

Can someone verify the Barron's book has this wrong? They used the opposite formula for each problem.
Number 15 the answer should be 2 because it has twice the area.
Number 12 should be 4 because it's twice the diameter which would equal 4x the area.

Area is expressed in this case as inches squared for problem 15, and diameter is simply in inches problem 12.

For problem 15, technically speaking, cylinder B is not twice the area, but more then twice. (6^2=36) is not twice the area of (3^2=9). if it was twice the area, then cylinder B would be 18, but its not. The book has it correct.

For problem 12, its only asking to find the how much cylinder A will rise if B is pressed down by one inch, not the entire height of the cylinder. The correct answer will be cylinder A rising 2 inches per 1 inch of B pressing down.

Just be careful of exponents on problem 15 which is what I'm guessing it was confused you. hope that helps.

 

[Brand0034]

Area is expressed in this case as inches squared for problem 15, and diameter is simply in inches problem 12.

For problem 15, technically speaking, cylinder B is not twice the area, but more then twice. (6^2=36) is not twice the area of (3^2=9). if it was twice the area, then cylinder B would be 18, but its not. The book has it correct.

For problem 12, its only asking to find the how much cylinder A will rise if B is pressed down by one inch, not the entire height of the cylinder. The correct answer will be cylinder A rising 2 inches per 1 inch of B pressing down.

Just be careful of exponents on problem 15 which is what I'm guessing it was confused you. hope that helps.

But for 15 it gives the area of the cylinders so why would you square the area? Area is piR^2. There’s no need to square the given value because it’s not the radius.
And for 12 it gives you the diameter so then you would have to convert that to area. The book just divides the two numbers which is incorrect. That’s the ratio of diameters it finds, not the ratio of area to each cylinder.

 

[Brand0034]

It’d really be the volume, but the book is still wrong.
Fluids can’t compress so the volume input must equal volume output.
A1D1=A2D2
So take the area and multiply by the distance it’s pushed down. #15 gives the areas 6 and 3
A1D1=A2D2
6(1”)=3(D2)
D2=2”
#12 gives the diameters of 3 and 6. Meaning the radius of each will be 1.5 and 3. So A=pir^2
A=pi(1.5^2) and A=pi(3^2)
So once again A1D1=A2D2
Pi(1.5^2)D1=pi(3^2)(1)
2.25piD1=9pi
D1=4
If I’m missing something please explain but I just can’t see how the book is right. It’s solving the problems reverse and squaring the area which makes no sense. These problems are about volume.

 

[jlebsock]

It’d really be the volume, but the book is still wrong.
Fluids can’t compress so the volume input must equal volume output.
A1D1=A2D2
So take the area and multiply by the distance it’s pushed down. #15 gives the areas 6 and 3
A1D1=A2D2
6(1”)=3(D2)
D2=2”
#12 gives the diameters of 3 and 6. Meaning the radius of each will be 1.5 and 3. So A=pir^2
A=pi(1.5^2) and A=pi(3^2)
So once again A1D1=A2D2
Pi(1.5^2)D1=pi(3^2)(1)
2.25piD1=9pi
D1=4
If I’m missing something please explain but I just can’t see how the book is right. It’s solving the problems reverse and squaring the area which makes no sense. These problems are about volume.

I see what your saying. I have the same book and sort of took it as truth. here is a video I found that goes along with what you were saying.

 

[Brand0034]

Yea it's Pascal's Law. I remember doing this in Physics 1, I just couldn't find a video asking about the distance the piston will travel. Everything dealing with Pascal's law is P1=P2 and only calculates pressure or area/diameter. I'm almost positive the book is wrong, just annoying how a professional book messes up twice on the same problem.
Reminds me of organic chemistry where you could ask three professors how to do a problem and get three different answers....