Quick math question.

<p>How do you do the math question where it says Bob can make 8 toys in 2 hours and Mike can make 5 toys in 4 hours, how many toys of them working together can be made in 1 hour. What's the general math formula for these types of problems?</p>

<p>Proportions.</p>

<p>Is that a question you made up since the answer i got was 5 1/4 </p>

<p>Okay so 8/2 = x/1 </p>

<p>you get x = 4 </p>

<p>5/4=x/1</p>

<p>x = 5/4</p>

<p>or 5 toys since you cant have 1/4 of a toy
add them both and you get 5 1/4</p>

<p>Yeah I made it up. I've been doing a lot of prepping, but I didn't really need prepping for math, but I'm just going through some problems which I couldn't get. I thought that there was some other formula for doing this. You could use the proportions with say lawn mowing, 5 square feet in 1 hour and 10 square square feet in an hour. I remember something about if they were both 5, it would be their average 2.5 in one hour. But if it's more than 5, then it's above the average.</p>

<p>You can easily figure out any math problems on the SAT by doing them in a roundabout way.</p>

<p>How about: (rate1 + rate2) * time</p>

<p>(8/2 + 5/4) * 1 hour = 5 1/4</p>

<p>Well I found one online
Example : If Johnny can mow the lawn in 30 minutes and with the help of his brother, Bobby, they can mow the lawn 20 minutes, how long would take Bobby working alone to mow the lawn?</p>

<p>(A) 1/2 hour (B) 3/4 hour (C) 1 hour (D) 3/2 hours (E) 2 hours</p>

<p>Let r = 1/t be Bobby's rate. Now, the rate at which they work together is merely the sum of their rates:</p>

<p>Total Rate = Johnny's Rate + Bobby's Rate</p>

<p>1/20 = 1/30 + 1/t
1/20 - 1/30 = 1/t
(30 - 20)/(30)(20) = 1/t
1/60 = 1/t
t = 60 </p>

<p>Hey alpha, do you have any other formulas like the 2xy/x+y for speed and the one you just gave?</p>

<p>
[quote]
Hey alpha, do you have any other formulas like the 2xy/x+y for speed and the one you just gave?

[/quote]

Not really, the one I just gave was impromptu. But as Liist said, every problem can be solved in a "roundabout" way. Once you understand the methodology behind solving a problem, it will stay with you.</p>

<p>Well, what more prepping can I do? I've finished all the BlueBook Math and CR tests. I haven't really done writing at all because I'm not concerned much with it. I've done some, but I didn't want to put the time into knowing idioms and using certain phrases after certain parts of sentences because I wanted to spend more of that time on CR and vocab; otherwise, I have a very strong sense of grammar.</p>

<p>I have the Official Online Practice Test(already finshed its math) for CR as the last CollegeBoard test I can take at the moment, but I have to print out the passage, otherwise it's hard to read the passage and cross out wrong choices. I can also look over RocketReview's 323 words(to make sure I have them memorized), look over Princeton Review's words(to make sure again), and then try to cram Sparknotes words. I might also wake up early in the morning tomorrow and take a few practice problems to get myself ready. Wow I can't believe I'm taking this thing tomorrow. I just won't know what to feel if I come across a math section that I have no clue how to answer or find myself daunted by the hard vocab of the sentence completions(even medium questions can pose problems), which means that I have to get basically all the passage questions right. I'm trying to get a 700, which basically means I can't miss more than 5 on math and can't miss more than 8 on CR. For math, I am very good at, but I definitely don't want to come across one of those problems which I Have no clue on. The hardest will be the hard grid ins since you don't have any answer choices to work with.</p>

<p>Since you are testing tomorrow, take this time to relax your nerves. Review your problem areas, but don't stress over them. Make sure you get a good amount of sleep. Knowing that your preparation has been thorough, you should go into the test with confidence in your ability. Focus and apply what you have learned, and you will receive the fruit of your labor.</p>

<p>Isn't there an instance when you set something equal to 1? As in 1 complete job?</p>

<p>yea i think when you want to find how many they can do in one hour..</p>

<p>In 2 hours, Bob makes 8 toys.
So in 1 hor, Bob makes 4 toys.</p>

<p>In 4 hours, Mike makes 5 toys.
So in 1 hour, Mike makes 1.25 toys.</p>

<p>Therefore, total=5.25 toys.</p>

<p>But since you can't have a quarter of a toy, the answer ought to be 5 toys.</p>