Search found 17 matches
Combination
Hello everyone, Mathey is traveling by a country where the coins are issued in only two values, 2c and 5c, which are made of iron and copper, respectfully. If he has 10 iron coins and 10 copper coins, how many different sumons between 1c and 70c can he combine with his coins. (A) 66 (B) 67 (C) 68 (D...
- by RobertP
Sun Feb 21, 2016 3:44 pm- Forum: Problem Solving
- Topic: Combination
- Replies: 2
- Views: 1336
Rates of Machines
Hello everyone,
Machine A takes double the time than machine B to produce N items. Wokring together at their respective rates, A and B can produce 5 items in 3 days. How many days will it take for machine A to produce 5 items?
(A) 5
(B) 8
(C) 9
(D) 12
(E) 18
- by RobertP
Sun Feb 21, 2016 3:35 pm- Forum: Problem Solving
- Topic: Rates of Machines
- Replies: 2
- Views: 1444
Distance of trains
Hello everyone, A high speed train will take X hours to run Z km which separates city A from city B. A conventional train will take y hours to travel the same distance. If the high speed train leaves city A to city B and the conventional train leaves city B to city A at the same time, how many more ...
- by RobertP
Sun Feb 21, 2016 3:27 pm- Forum: Problem Solving
- Topic: Distance of trains
- Replies: 8
- Views: 3471
Roots of equation
Hello everyone,
If r and s are the roots of the equation x^2 + bx + c = o, where b and c are constants, is rs < 0?
(1) B < 0
(2) C < 0
In all honestly, I didn't even understand what the question is asking for. Could someone help me out?
Thnx
- by RobertP
Sun Feb 21, 2016 1:18 pm- Forum: Data Sufficiency
- Topic: Roots of equation
- Replies: 3
- Views: 1347
Property of Numbers
Hello everyone,
Can some one please help me understand the solution of the problem bellow?
Thank you!
If N = 3^8 - 2^8, which of the following is not a factor of n?
A) 97
B) 65
C) 35
D) 13
E) 5)
Answer: C
- by RobertP
Thu Feb 11, 2016 12:23 pm- Forum: Problem Solving
- Topic: Property of Numbers
- Replies: 3
- Views: 1057
- by RobertP
Fri Feb 05, 2016 7:51 am- Forum: Problem Solving
- Topic: Word problem - rates
- Replies: 7
- Views: 1735
Hi Rich,
To the videos posted on the link bellow:
http://www.gmatprepnow.com/module/gmat-word-problems.
- by RobertP
Fri Feb 05, 2016 7:03 am- Forum: Problem Solving
- Topic: Word problem - rates
- Replies: 7
- Views: 1735
Word problem - rates
Hello everyone! Ok, this question is actually from the GMAT review book 2016. I am only posting this here because I tried the method demonstrated on the videos, but it is just not working so I would like to grasp what I am doing wrong. Could someone help me, please? Thank you! Working simultaneously...
- by RobertP
Thu Feb 04, 2016 5:03 pm- Forum: Problem Solving
- Topic: Word problem - rates
- Replies: 7
- Views: 1735
Is x^2 equal to xy?
Hello everyone.
Is y^2 equal to xy?
(1) x^2 – y^2 = (x + 3)(y – 3)
(2) x = y
[spoiler]For some reason I think the anwer is already in the statement, can somone check my logic. y^2=xy => y^2/y = x => y = x. Is this logic correct? [/spoiler]
- by RobertP
Wed Feb 03, 2016 9:17 am- Forum: Data Sufficiency
- Topic: Is x^2 equal to xy?
- Replies: 7
- Views: 2176
Robinsons
Hello everyone,
The Robinsons have had three children of different ages. How old is the youngest today?
(1) The two older children have, together, 16 years
(2) The two younger children have, together, 9 years
- by RobertP
Wed Feb 03, 2016 9:14 am- Forum: Data Sufficiency
- Topic: Robinsons
- Replies: 2
- Views: 1383
Ratio
Hello everyone! Ok, this is exactly a kind of question that I have a lot of dificulites answering, especially because it involves more of a math logic that math skills per say. Anyone have any suggestions how I can improve this skill? Thank you! Certain store sold copies of the newspaper A for USD 1...
- by RobertP
Tue Jan 26, 2016 4:33 pm- Forum: Problem Solving
- Topic: Ratio
- Replies: 4
- Views: 1721
Investing
Hello everyone. I solved this by pluging values. Any other methods to easily solve this? Thnx If R dollars were invested in a fund with 10% return and S dollars are invested in saving account with 8% return during the same period, the return of the fund will surpass of the saving account by USD$ 56....
- by RobertP
Tue Jan 26, 2016 4:28 pm- Forum: Problem Solving
- Topic: Investing
- Replies: 1
- Views: 923
Marty, thank you very much. I was having a really hard time with this question. I understood everything and there were some concepts such as similar triangles that I did not know of. However there was once passage that I did not understand: 1/2 = x² x = √(1/2) = √2/2 Why is the square roote of ...
- by RobertP
Sun Jan 24, 2016 3:02 pm- Forum: Problem Solving
- Topic: Geometery - Triangles
- Replies: 4
- Views: 1473
Geometery - Triangles
In the figure bellow the triangles ABC and MNP are isosceles. AB || MN, BC || NP, the length of AC is 7 and the length of BY is 4. If the area if the white region is equal to the area of the grey region, what is the length of MP? (A) 2 * 2^(1/2) (B) 2 * 7^(1/2) (C) ( 2 * 3^(1/2) ) / 3 (D) (7 * 2^(1/...
- by RobertP
Sun Jan 24, 2016 11:31 am- Forum: Problem Solving
- Topic: Geometery - Triangles
- Replies: 4
- Views: 1473
Inequalities
Anyone know how to solve this one?
Which inequality represents the expression bellow:
-2 < x < 12
a) x – 10 < 2
b) x-5 < 7
c) x-7 < 5
d) x -2 < 10
e) None of the above.
- by RobertP
Sun Jan 24, 2016 11:26 am- Forum: Problem Solving
- Topic: Inequalities
- Replies: 1
- Views: 1001