Anonymous

Anonymous asked:

if it is now 4:00 p.m Saturday, in 253 hours from now, what time and day will ot be ? (assume no daylight saving time changes in the period? A (5:00a.m Saturday)B (1:00a.m Sunday) C (5:00pm Tuesday)D (1:00a.m Wednesday) E (5:00am Wednesday)

240 hours from now will be 10 days from now at 4pm. Another 13 hours gets us to 253 hours. 13 hours after 4pm is 5am the next day. So the answer you seek will be 5am 11 days after Saturday.

7 days after Saturday is Saturday again, then 4 more days gets you to Wednesday.

Anonymous

Anonymous asked:

if the length and width of rectangle A are 10 percent less and 30 percent less, respectively, than the length and width of rectangle B, the area of A is equal to what percent of area of B? Why it is (63%)

PLUG IN!!!!

Say rectangle B has sides of 10 and 10, so it’s area is 100. The sides of rectangle A, then, will be 9 and 7—10% and 30% less than 10, respectively. The area of rectangle A will be 63. 

Now here’s the real beauty of making B a 10 by 10 square: 63 is what percent of 100? EASY! 63%.

New rule about images

Hi guys,

Lately, a bunch of people have been submitting questions that just say “Can I post a picture?” or something to that effect—then putting phone pictures of their questions in the comments box. I am revising my policy on that to make this site more useful for everybody. Here’s the new rule:

You still must type out all the text in the question. Then, at the end of that, say something like “I’ll put the figure in the comments.”

That way, anyone Googling the question later can still find it, which means the mission of this site (to provide a useful prep resource for everyone) is still achieved. When you just post a picture in the comments and I answer it, the question is completely un-Googleable.

Thanks for understanding!

Anonymous

Anonymous asked:

Of 5 employees, 3 are to be assigned an office and 2 are to be assigned a cubicle. If 3 of the employees are men and 2 are women, and if those assigned an office are to be chosen at random, what is the probability that the offices will be assigned to 2 of the men and 1 of the women?

See here.

Anonymous

Anonymous asked:

Hey Mike the general consensus on College Confidential was that form S on the PSAT had a difficult Math Section. What score do you suspect 6 questions omitted would be as well as 6 omitted and 4 wrong.

I don’t like to play the “how harsh will the curve be?” game. I didn’t take the test myself, and I’ve learned over years of doing this not to trust what others say—it’s too easy to find someone saying what you want to hear.

6 omitted is a raw score of 32. 6 omitted and 4 wrong is a raw score of 27 or 28, depending on how many of those 4 wrong were multiple choice.

Based on the scoring table for the free practice PSAT that was handed out this year, that’s either high 600s, or right around 600.

Anonymous

Anonymous asked:

THE length of a rectangle is increased by 10 percent and the width is decreased by 10 percent. what percent of the old area is the new area?

Plug in! Say the original rectangle is a 10 by 10 rectangle (AKA a square—yes, a square is a rectangle). That rectangle has an area of 100.

Now increase the length by 10% and decrease the width by 10%—you end up with an 11 by 9 rectangle. That’s got an area of 99.

99 is what percent of 100? 99%, of course.

Anonymous

Anonymous asked:

Mike did you program your main website yourself? I noticed you were using wordpress, just curious because I'm a self taught programmer and was wondering if you were also.

I taught myself a little CSS and HTML, but mostly I just find plug ins that do what I want them to do. I wish I was more of a programmer than I am.

7amoodo asked:

In the figure above, the smaller circles each have radius 3. They are tangent to the larger circle at points A and C, and are tangent to each other at point B, which is the center of the larger circle. What is the perimeter of the shaded region?(A) 6 (B) 8 (C) 9 (D) 12 (E) 15 

You’ll have to put the figure in the comments…

Anonymous

Anonymous asked:

To make an orange dye, 3 parts of red dye are mixed with 2 parts of yellow dye, to make a green dye, 2 parts of blue dye are mixed with 1 part of yellow dye. If equal amounts of green and orange are mixed, what is the proportion of yellow dye in the new mixture? (3/16) (1/4) ( 11/30) (3/8)(7/12)

OK, so let’s say there are 15 gallons of red dye (that’s 9 gallons red and 6 gallons yellow) and 15 gallons of green dye (that’s 10 gallons blue and 5 gallons yellow). All told, you’ve got 30 gallons of the mix, 11 of which are yellow. 11/30 is your answer.

Anonymous

Anonymous asked:

A woman drove to work at an average speed of 40 miles per hour and returned along the same route at 30-miles per hour. If her total traveling time was 1hour, what was the total number of miles in the round trip?

Here’s how I’d do this. First, plug in a distance between home and work that’s easy to work with, like 120 miles. If the trip is 120 miles to work and 120 miles back, then it takes her 3 hours to get to work, and 4 hours to get back—a total trip time of 7 hours.

Since we know the trip only took 1 hour, her work must be 1/7 of the distance from home that we assumed—120/7 miles. Since the question asks for the total distance in the round trip, we multiply that by 2 and get 240/7.

Anonymous

Anonymous asked:

From a math 1 test: The number 3, 5, and 7 are three consecutive odd numbers that are prime. How many other triplets of consecutive odd numbers greater than 1 consist entirely of primes. I sort of reasoned that there are no others because after testing a few numbers, it doesn't seem likely, but how do we prove it?

Was this a question on an official practice test? You’re right, there are no other triplets like that—you can’t make 3 consecutive odd integers greater than 3 that won’t contain a multiple of 3. 

The proof goes like this. Say your consecutive odd numbers are x, x + 2, and x + 4, where x is an odd number greater than 3. x can’t be a multiple of 3, or it won’t be prime, so x is either 1 greater than a multiple of 3, or 2 greater than a multiple of 3.

If x is 1 greater than a multiple of 3 (e.g. 7), then x + 2 will be a multiple of 3.

If x is 2 greater than a multiple of 3 (e.g. 11), then x + 4 will be a multiple of 3. 

So…yeah. After 3, 5, 7, there are no such prime triplets.

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