Search found 8 matches
There is a pattern that develops here: 10 - 01 = 9 20 - 02 = 18 30 - 03 = 27 40 - 04 = 36 50 - 05 = 45 60 - 06 = 54 70 - 07 = 63 80 - 08 = 72 90 - 09 = 81 As you can see the difference between the 2 digits is 9*(difference of digits) So if you ever get a question like this again, the quick way is to...
- by KeyserSoze525
Mon Oct 27, 2008 10:51 am- Forum: Problem Solving
- Topic: two digit positive integer in OG 11- 228
- Replies: 4
- Views: 5502
I think I figured it out. If the rate varies by A^2 and 1/B then the rate is equal to: R = A^2/B or R = A/sqrt(B) If you increase B by 100% or double it: R = A^2/2B or R = A/sqrt(2B) or R= A/sqrt(2)*sqrt(B) In order to maintain the rate, A needs to be multiplied by sqrt(2) so an increase of sqrt(2) ...
- by KeyserSoze525
Mon Oct 27, 2008 7:57 am- Forum: Problem Solving
- Topic: percent-ratio: chemical properties
- Replies: 3
- Views: 1477
You have 12 Blue and Y yellow balls. The probability of picking a blue ball is: P(B) = 12/(12+Y) (12 Blue balls out of a total possible 12 + Y balls) We also know that P(B) < 2/5 so: 12/(12+Y) < 2/5 Cross multiply: 60 < 24 + 2Y Simplify: 36 < 2Y or 18 < Y Since Y must be greater than 18, the smalles...
- by KeyserSoze525
Mon Oct 27, 2008 7:19 am- Forum: Problem Solving
- Topic: probability
- Replies: 3
- Views: 3139
- by KeyserSoze525
Mon Oct 27, 2008 7:04 am- Forum: Problem Solving
- Topic: percent-ratio: chemical properties
- Replies: 3
- Views: 1477
2^x - 2^(x-2) = 3(2^13) Using the exponent rule x^a * x^b = x^(a+b): 2^x - 2^x*2^-2 = 3(2^13) Factor out 2^x from the left side: 2^x (1 -2^-2) = 3(2^13) Simplify: 2^x * (1 - 1/4) = 3(2^13) 2^x * 3/4 = 3(2^13) Multiply both sides by 4 or 2^2: 2^x * 3 = 2^2 * 3(2^13) Divide both sides by 3: 2^x = 2^2 ...
- by KeyserSoze525
Mon Oct 27, 2008 6:49 am- Forum: Problem Solving
- Topic: exponents
- Replies: 5
- Views: 1576
The question says there are 4 Entrees and 5 Sides. A meal consists of 1 Entree and 2 Sides. So the setup would be: _ _ _ E S S For the Entrees, you would calculate 4 choose 1 or 4C1 = 4!/1!*(4-1)! = 4 For the Sides, you would calculate 5 choose 2 or 5C2 = 5!/2!*(5-2)! = 10 So the answer is 4*10 = 40
- by KeyserSoze525
Mon Oct 27, 2008 4:42 am- Forum: Problem Solving
- Topic: Combo Probelm from GMAT Prep
- Replies: 3
- Views: 1214
- by KeyserSoze525
Mon Oct 27, 2008 4:24 am- Forum: Problem Solving
- Topic: Probability Question !
- Replies: 8
- Views: 4630
30. Set B has three positive integers with a median of 9. If the largest possible range of the three numbers is 19, given a certain mean, what is that mean? (A) 22 (B) 10 (C) 9.6 (D) 9 (E) It cannot be determined with the information given You have the set B {x,9,y} where all elements are positive ...
- by KeyserSoze525
Mon Oct 27, 2008 3:49 am- Forum: Problem Solving
- Topic: Whats the Mean
- Replies: 11
- Views: 1905