Last visit was: 07 Nov 2024, 15:47 It is currently 07 Nov 2024, 15:47

Close

GRE Prep Club Daily Prep

Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GRE score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel
Verbal Expert
Joined: 18 Apr 2015
Posts: 29907
Own Kudos [?]: 36147 [3]
Given Kudos: 25889
Send PM
avatar
Intern
Intern
Joined: 24 May 2019
Posts: 28
Own Kudos [?]: 39 [4]
Given Kudos: 0
Send PM
avatar
Intern
Intern
Joined: 02 Sep 2020
Posts: 14
Own Kudos [?]: 9 [0]
Given Kudos: 0
Send PM
Verbal Expert
Joined: 18 Apr 2015
Posts: 29907
Own Kudos [?]: 36147 [0]
Given Kudos: 25889
Send PM
Re: The monthly incomes of A and B are in the ratio 3 : 2, and t [#permalink]
Expert Reply
The answer is A Sir NOT D
avatar
Intern
Intern
Joined: 02 Sep 2020
Posts: 14
Own Kudos [?]: 9 [0]
Given Kudos: 0
Send PM
Re: The monthly incomes of A and B are in the ratio 3 : 2, and t [#permalink]
There is a similar question 5 questions back on previous page,same situation.

How can it be A?ratios can be anything

Posted from my mobile device Image
Intern
Intern
Joined: 11 Aug 2020
Posts: 45
Own Kudos [?]: 76 [4]
Given Kudos: 17
Send PM
Re: The monthly incomes of A and B are in the ratio 3 : 2, and t [#permalink]
4
vaishar3 wrote:
There is a similar question 5 questions back on previous page,same situation.

How can it be A?ratios can be anything

Posted from my mobile device


I agree with that, however, in this case, there are several ingredients that allows finding a pattern which is always true:

Let's suppose that the relation between the total income of A and B can be written as:

\(3x + 2x = I\), with \(I = A_{I} + B_{I}\)
In this case, the total income of \(A\) and \(B\) are given by:
\(A_{I} = \frac{3*I}{5}\)
\(B_{I} = \frac{2*I}{5}\)
And the total expenditures: (\(E\))
\(4y + 3y = E\), with \(E = A_{E} + B_{E}\)
that could be written as:
\(A_{E} = \frac{4*E}{7}\)
\(B_{E} = \frac{3*E}{7}\)
Now, for each person, we will calculate their savings equation:
\(A_{S} = \frac{3*I}{5}-\frac{4*E}{7}\)
\(B_{S} = \frac{2*I}{5}-\frac{3*E}{7}\)
In order to work with friendly numbers, we are going to multiply each equation by 35:
\(35*A_{S} = 21*I-20*E\)
\(35*B_{S} = 14*I-15*E\)
Now, we can substract both equations:
\(35*A_{S} - 35*B_{S} = 21*I-14*I - 20*E-15*E\)
Solving:
\(35*A_{S} - 35*B_{S} = 7*I - 5*E\)
(the following step is not necessary)
\(A_{S} - B_{S} = \frac{7*I - 5*E}{35}\)
In this case, we now that I>E (they told us), therefore, this expression \(7*I - 5*E\) is always positive. Finally, we can say that no matter what kind of numbers do you pick, the savings of A will be always greater than B.
avatar
Intern
Intern
Joined: 31 Dec 2019
Posts: 4
Own Kudos [?]: 0 [0]
Given Kudos: 49
Send PM
The monthly incomes of A and B are in the ratio 3 : 2, and t [#permalink]
Savings Of A=3x-2y
Savings of B=2x-3y
Using these equations If I take x=10 and y=5
Savings of A=5
Savings of B=5
In this case ans is C
But for x=5 and y=2
Savings of A>savings of B
Ans is A for this case
So shouldn’t be D is the ans?

Posted from my mobile device
Verbal Expert
Joined: 18 Apr 2015
Posts: 29907
Own Kudos [?]: 36147 [1]
Given Kudos: 25889
Send PM
Re: The monthly incomes of A and B are in the ratio 3 : 2, and t [#permalink]
1
Expert Reply
OE

Let the income of A and B be 3s and 2s, respectively, and let their expenditures be 4t and 3t. Then since savings is defined as income minus expenditure, Column A = the saving of A = 3s – 4t, and Column B =
saving of B = 2s – 3t.

Column A is greater than Column B when 3s – 4t > 2s – 3t, or s > t.

Since money is positive, s and t are positive. Since income is greater than expenditure (given), the Income of B = 2 s > Expenditure of B = 3 t. Hence, s > 3 t/2. Clearly, s > t. Since we know that Column A >

Column B when s > t, the answer is (A)
User avatar
GRE Prep Club Legend
GRE Prep Club Legend
Joined: 07 Jan 2021
Posts: 5010
Own Kudos [?]: 74 [0]
Given Kudos: 0
Send PM
Re: The monthly incomes of A and B are in the ratio 3 : 2, and t [#permalink]
Hello from the GRE Prep Club BumpBot!

Thanks to another GRE Prep Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
Prep Club for GRE Bot
Re: The monthly incomes of A and B are in the ratio 3 : 2, and t [#permalink]
Moderators:
GRE Instructor
77 posts
GRE Forum Moderator
37 posts
Moderator
1111 posts
GRE Instructor
234 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne