Search found 17 matches
Using (1):
x5 = x4 / 2
Compare to:
x5 = x4 / (x4+1)
Basically, 2 = x4 + 1 => x4=1
(1) says that previous value is 2 times the current value. Starting with x4, we get x3=2, x2=4, x1=8.
C
- by alescau
Mon Sep 15, 2008 2:40 pm- Forum: Data Sufficiency
- Topic: gmatprep - sequence ds
- Replies: 4
- Views: 2031
(160pi – 40pi) + (120pi – 30pi)mals24 wrote: Difference = (160pi – 40pi) – (120pi – 30pi) = 210pi
just take the length of the rope touching the circles to be 3/4 of circumference.
- by alescau
Mon Sep 15, 2008 12:04 pm- Forum: Problem Solving
- Topic: Two circular disks
- Replies: 3
- Views: 1323
since the coefficients are prime numbers, nothing simplifies.
to make the equality stand, x=4*7, y=3*7, z=3*4. add them up and get 61.
- by alescau
Mon Sep 15, 2008 11:58 am- Forum: Problem Solving
- Topic: Least possible value
- Replies: 4
- Views: 7719
I think it is A.
p=8x+5=4(2x)+4+1=4(2x+1)+1
remainder when p is divided by 4 is 1.
II does not tell us anything.
- by alescau
Mon Sep 15, 2008 11:22 am- Forum: Data Sufficiency
- Topic: GMAT Prep
- Replies: 5
- Views: 1601
each line needs two data points to be defines.
(1) tells us something about k, not m.
(2) tells us about k.
we have three points for k, but still one for m. thus we can not tell what m looks like.
thus, E.
- by alescau
Mon Sep 15, 2008 11:14 am- Forum: Data Sufficiency
- Topic: DS - Coordinate Geometry
- Replies: 3
- Views: 1460
in problems like this you need to consider numbers that differ in behavior. if x>1, x^2>x, 1/x<1 if x<1, x^2<x, 1/x>1 so, if x>1, 1/x<1. the other ones >1. we do not have an answer choice that has 1/x as the lowest number. if x<1, x^2 is the lowest. possible choices are I and II. just consider 2x < ...
- by alescau
Mon Sep 15, 2008 11:09 am- Forum: Data Sufficiency
- Topic: GMAT Prep Integers
- Replies: 2
- Views: 1492
3 largest ones added together should be more than 3x.
(A) 5x=6x+?? Wrong
(B) 5x=4x+?? We can solve this.
Ans.B
- by alescau
Mon Sep 15, 2008 10:44 am- Forum: Problem Solving
- Topic: Temperature average problem
- Replies: 2
- Views: 5608
- by alescau
Mon Sep 15, 2008 1:41 am- Forum: Data Sufficiency
- Topic: symbol
- Replies: 3
- Views: 1280
(1) doesn't give us anything to work with.
(2) (87*3 + x)/4 = 90. We can solve this, thus we can answer the question using this.
87*3 is the same as the sum of the scores from the first three tests, b/c (Sum first three)/3=(Avg first three)
- by alescau
Mon Sep 15, 2008 12:01 am- Forum: Data Sufficiency
- Topic: Riya's score
- Replies: 1
- Views: 1286
(2) Simply replace ° with -.
(1) Notice that the condition is not satisfied by + and by x, therefore it must be - as in case (1).
k - l - m = 2k - l - m
now this would be true for k = 0, but the question says that it must hold for all k, thus we can say with certainty NO. Ans. D
- by alescau
Sun Sep 14, 2008 11:55 pm- Forum: Data Sufficiency
- Topic: symbol
- Replies: 3
- Views: 1280
first team plays 2 games * 5 teams = 10 games
second team plays 2 games * 4 teams = 8 games (exclude first team since they played)
....
in essence 2 (5+4+3+2+1) = 30 games total
- by alescau
Sun Sep 14, 2008 11:03 pm- Forum: Problem Solving
- Topic: PS - League Results
- Replies: 6
- Views: 1674
- by alescau
Sun Sep 14, 2008 8:04 pm- Forum: Problem Solving
- Topic: Digit problem
- Replies: 7
- Views: 5414
a step for speed would be to multiply Eq 1 by 1.5 and then subtract Eq 2 to eliminate y.cramya wrote: 12x+10y = 38 Eq 1
20x+15y = 60 Eq 2
- by alescau
Sun Sep 14, 2008 6:01 pm- Forum: Problem Solving
- Topic: PS- map sell problem
- Replies: 6
- Views: 2444
ok, in general every third number in sequence is divisible by three. by taking n, n+1, n+2 you are sure that one of them is divisible by 3. you can add or subtract 3 from either of them without changing divisibility. n is the same as n-6, n-3, n+3, n+6... n+1 is the same as n-5, n-2, n+4, n+7... n+2...
- by alescau
Sun Sep 14, 2008 5:55 pm- Forum: Problem Solving
- Topic: If n is an integer greater than 6 + divisibility question
- Replies: 29
- Views: 18759
- by alescau
Sun Sep 14, 2008 4:06 pm- Forum: Problem Solving
- Topic: tree problem
- Replies: 8
- Views: 1888