SAT Prep: Test 2 Section 6 Part 2 Video

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SAT Prep: Test 2 Section 6 Part 2

I think I rushed the end of that problem just to finish in the 10 minute YouTube timelimit. And I just want to make sure you understand because I did all over the place. We said well you know, white to brown is two to three and then we just kind of soften Y=2/3 times the brown. And we also say the total number of baskets is white +brown, white is 2/3 of the number of brown. So 2/3 brown+3/3 brown that equals 5/3 of brown as equal to the total or we could multiply both side of this times 3/5. Let us say that the brown is equal to the total times 3/5. It says we can’t have a fractional number of brown eggs, the total has to be divisible by five. And if you look at the choices the only number that is not divisible by five is choice B, is 12. All the other choices are divisible by five so they could’ve been possible choices. Let’s move on to the next, I will do it in green, seven. If 18 root 18, 18 times the square root of 18 is equal to R times the square root of T. Where R and T are positive integers and we also know that R is greater than T, which of the following can be the value of R times T? So this is interesting, R can’t equal T otherwise they would both be a T. But one thing, one interesting that we kind of try doing --. Let’s see how can we think about this problem, well we know that R and T are positive integers. So what could R and T be? 18 root 18, so we could factor this more, we could say that this is the same thing as 18 times. 9(2) in which case it is the same thing as 18, square root of 9 is 3(3) times root two. That is 3(18) that is 54 root two. So this would satisfy this format so we could say R is 54 and T is two. In which case RT would be 108 let’s see if that is the choice. And it is a choice, so we are done because that could be the value of RT. Maybe I just stumble on it, but that is the answer. I just simplified this a little bit, I said that 18 root 18 is the same thing as 54 root two. So R is 54, T is two if you multiply them you get 108 and now it’s choice C. Problem number eight. Which I will do in yellow, fancy graph drawn there, now the triangle inside that triangle. Let us see what they grow to addition to that, so this angle is B, this angle is C, this angle is A. This angle is B, this is B and this is A, and they want to know. And the figure above, what is the value of C in terms of A and B. And I call this if you watch my jump through videos, this to me is the angle game. Because we are just going to try t o figure out as many angles as we can and eventually we’ll hopefully be able to figure out what C is. So we know this is B and all of these combined formed this supplementary angle 180. So we know that this angle right here is 180 – B – B so it’s – 2B. That’s this angle right there and then what is this angle right here? Well this angle is 180 did that help us? Is that the way to help me with this problem? We’ll just keep this is 180 – A – C, I don’t think that helps us already. This angle right here, is going to be 180 – A – B, I should drawn this bigger. This angle right here is also because we have this inner triangle right here that is also is going to be 180 – A – B. This angle here is going to be 180 this angle minus this angle. So it’s 180 minus angle which we figure it out was 180 – A – B and we just figure it out that. Because that was part of this triangle, so it’s 180 – 180 – A – B minus this angle here. Which is also 180 – A – B, it’s really – 2(180 – A – B) and if you simplified that we get 180 minus we have this twice you could just simplify it. It’s 2(180+2A+2B) let’s take a couple of steps because a negative distributes and then you have two A’s and two B’s. And then if we simplify this, we get, so this is 180-360, so you get 2A+2b-180. And I had to simplify this – is this angle. And then we also know that this angle that we just figured out +B+C=180, +B+C=180. So let me move up here, so if you want to solve for C we just subtract everything. We subtract all of this from the other side, so C is going to be equal to 180-2A-2B+180 because I am subtracting this from the other side or that will make it +180. Minus B again, so if we simplify this, so C = 360-2A and then -3B. Let’s see if that is a choice, choice E is 360 – 2A -3B so I haven’t made a silly error which I thought I made. So you really just kind of keep and then you figure out this angle terms of A and B. If you figure out this angle in terms of A and B and then if you figure out this angle in terms of this angle and this angle. So you just keep using the angles of the triangle up to 180 property of triangles. Go to the next page, now we are on the free answer questions. So they say T³=351 what is 40³? So the slow way of doing this is to try to figure out what T is, the fast way is well 40³ if T³=351 then 40³ is multiplied both sides times four. And so the 351(4), 4(1)=4, 4(5)=20, 3(4)=12, 1,404 that is the answer. And I have 40 seconds left so I will wait for the next video, see you soon.

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I think I rushed the end of that problem just to finish in the 10 minute YouTube timelimit. And I just want to make sure you understand because I did all over the place. We said well you know, white to brown is two to three and then we just kind of soften Y=2/3 times the brown. And we also say the total number of baskets is white +brown, white is 2/3 of the number of brown. So 2/3 brown+3/3 brown that equals 5/3 of brown as equal to the total or we could multiply both side of this times 3/5.

Let us say that the brown is equal to the total times 3/5. It says we can’t have a fractional number of brown eggs, the total has to be divisible by five. And if you look at the choices the only number that is not divisible by five is choice B, is 12. All the other choices are divisible by five so they could’ve been possible choices.

Let’s move on to the next, I will do it in green, seven. If 18 root 18, 18 times the square root of 18 is equal to R times the square root of T. Where R and T are positive integers and we also know that R is greater than T, which of the following can be the value of R times T? So this is interesting, R can’t equal T otherwise they would both be a T. But one thing, one interesting that we kind of try doing --.

Let’s see how can we think about this problem, well we know that R and T are positive integers. So what could R and T be? 18 root 18, so we could factor this more, we could say that this is the same thing as 18 times. 9(2) in which case it is the same thing as 18, square root of 9 is 3(3) times root two. That is 3(18) that is 54 root two.

So this would satisfy this format so we could say R is 54 and T is two. In which case RT would be 108 let’s see if that is the choice. And it is a choice, so we are done because that could be the value of RT. Maybe I just stumble on it, but that is the answer. I just simplified this a little bit, I said that 18 root 18 is the same thing as 54 root two. So R is 54, T is two if you multiply them you get 108 and now it’s choice C.

Problem number eight. Which I will do in yellow, fancy graph drawn there, now the triangle inside that triangle. Let us see what they grow to addition to that, so this angle is B, this angle is C, this angle is A. This angle is B, this is B and this is A, and they want to know. And the figure above, what is the value of C in terms of A and B. And I call this if you watch my jump through videos, this to me is the angle game. Because we are just going to try t o figure out as many angles as we can and eventually we’ll hopefully be able to figure out what C is.

So we know this is B and all of these combined formed this supplementary angle 180. So we know that this angle right here is 180 – B – B so it’s – 2B. That’s this angle right there and then what is this angle right here? Well this angle is 180 did that help us? Is that the way to help me with this problem? We’ll just keep this is 180 – A – C, I don’t think that helps us already. This angle right here, is going to be 180 – A – B, I should drawn this bigger. This angle right here is also because we have this inner triangle right here that is also is going to be 180 – A – B.

This angle here is going to be 180 this angle minus this angle. So it’s 180 minus angle which we figure it out was 180 – A – B and we just figure it out that. Because that was part of this triangle, so it’s 180 – 180 – A – B minus this angle here. Which is also 180 – A – B, it’s really – 2(180 – A – B) and if you simplified that we get 180 minus we have this twice you could just simplify it. It’s 2(180+2A+2B) let’s take a couple of steps because a negative distributes and then you have two A’s and two B’s. And then if we simplify this, we get, so this is 180-360, so you get 2A+2b-180. And I had to simplify this – is this angle.

And then we also know that this angle that we just figured out +B+C=180, +B+C=180. So let me move up here, so if you want to solve for C we just subtract everything. We subtract all of this from the other side, so C is going to be equal to 180-2A-2B+180 because I am subtracting this from the other side or that will make it +180. Minus B again, so if we simplify this, so C = 360-2A and then -3B. Let’s see if that is a choice, choice E is 360 – 2A -3B so I haven’t made a silly error which I thought I made.

So you really just kind of keep and then you figure out this angle terms of A and B. If you figure out this angle in terms of A and B and then if you figure out this angle in terms of this angle and this angle. So you just keep using the angles of the triangle up to 180 property of triangles.

Go to the next page, now we are on the free answer questions. So they say T³=351 what is 40³? So the slow way of doing this is to try to figure out what T is, the fast way is well 40³ if T³=351 then 40³ is multiplied both sides times four. And so the 351(4), 4(1)=4, 4(5)=20, 3(4)=12, 1,404 that is the answer. And I have 40 seconds left so I will wait for the next video, see you soon.

Transcription by: Scribe4you Transcription Services