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 GMAT 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.

It appears that you are browsing the GMAT Club forum unregistered!

Signing up is free, quick, and confidential.
Join other 500,000 members and get the full benefits of GMAT Club

Registration gives you:

Tests

Take 11 tests and quizzes from GMAT Club and leading GMAT prep companies such as Manhattan GMAT,
Knewton, and others. All are free for GMAT Club members.

Applicant Stats

View detailed applicant stats such as GPA, GMAT score, work experience, location, application
status, and more

Books/Downloads

Download thousands of study notes,
question collections, GMAT Club’s
Grammar and Math books.
All are free!

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

The ratio of the number of plants that Keisha has to the number [#permalink]

Show Tags

27 Aug 2017, 02:03

1

This post was BOOKMARKED

00:00

A

B

C

D

E

Difficulty:

45% (medium)

Question Stats:

59% (01:44) correct 41% (01:44) wrong based on 59 sessions

HideShow timer Statistics

The ratio of the number of plants that Keisha has to the number of plants Sam has is 1:5. After Sam gives Keisha 5 plants, the ratio of plants Keisha has to the plants Sam has will be 2:7. How many more plants will Sam have than Keisha after 5 plants are given?

Re: The ratio of the number of plants that Keisha has to the number [#permalink]

Show Tags

27 Aug 2017, 02:08

The easiest number to work with is 50 Question is asking number of extra plants Sam has after the giving and taking process is done. Using Option C if 50 extra plants, then number of plants each of them has is 20 and 70 (2:7 ratio) Now since Sam has given 5 plants to Keisha, plants available to both of them before exchange is 70+5 = 75 and 20-5 = 15 Ratio of 15 and 75 is 1:5, which is matching our condition in question. Thus answer is Option C _________________

Abhishek Parikh Math Tutor Whatsapp- +919983944321 Mobile- +971568653827 Website: http://www.holamaven.com

The ratio of the number of plants that Keisha has to the number of plants Sam has is 1:5. After Sam gives Keisha 5 plants, the ratio of plants Keisha has to the plants Sam has will be 2:7. How many more plants will Sam have than Keisha after 5 plants are given?

A. 30 B. 45 C. 50 D. 60 E. 75

let the common ratio be x, so \(\frac{k}{s} = \frac{x}{5x}\) After s gives 5 to k, ratio becomes \(\frac{x+5}{5x-5}=\frac{2}{7}.....7x+35=10x-10.....3x=45...x=15\)

so the difference prior to exchange of 5 is (5-1)*x=4*15=60.. now when s gives 5 to k, difference reduces by 5+5=10...60-10=50 OR number = 15*1:15*4=15:75 after exchange of 5 it becomes = 15+5:75-5=20:70 so difference = 70-20=50

The ratio of the number of plants that Keisha has to the number of plants Sam has is 1:5. After Sam gives Keisha 5 plants, the ratio of plants Keisha has to the plants Sam has will be 2:7. How many more plants will Sam have than Keisha after 5 plants are given?

A. 30 B. 45 C. 50 D. 60 E. 75

Another approach...

Let K = # of plants that Keisha PRESENTLY has Let S = # of plants that Sam PRESENTLY has

The ratio of the number of plants that Keisha has to the number of plants Sam has is 1:5 We can write: K/S = 1/5 Cross multiply to get: 5K = S

After Sam gives Keisha 5 plants, the ratio of plants Keisha has to the plants Sam has will be 2:7 After Sam gives Keisha 5 plants, we have K + 5 = # of plants Keisha has S - 5 = # of plants Sam has So, we can write: (K +5)/(S - 5) = 2/7 Cross multiply to get: 7(K + 5) = 2(S - 5) Expand: 7K + 35 = 2S - 10 Simplify: 7K - 2S = -45

We now have two equations with 2 variables: 5k = S 7K - 2S = -45

Take bottom equation and replace S with 5K to get: 7K - 2(5K) = -45 Simplify: -3K = -45 Solve: K = 15

So, Keisha PRESENTLY has 15 plants, which means Sam PRESENTLY has 75 plants After Sam gives Keisha 5 plants, Keisha has 20 plants and Sam has 70 plants How many more plants will Sam have than Keisha after 5 plants are given? 70 - 20 = 50

The ratio of the number of plants that Keisha has to the number [#permalink]

Show Tags

27 Aug 2017, 11:22

HolaMaven wrote:

The ratio of the number of plants that Keisha has to the number of plants Sam has is 1:5. After Sam gives Keisha 5 plants, the ratio of plants Keisha has to the plants Sam has will be 2:7. How many more plants will Sam have than Keisha after 5 plants are given?

A. 30 B. 45 C. 50 D. 60 E. 75

Use x as a multiplier with the original ratio. Add and subtract 5 from that ratio, and set LHS equal to new ratio. Solve for x to yield how many plants each person had originally. Then calculate totals after the exchange.

Ratio of K's plants to S's plants:\(\frac{K}{S}\) = \(\frac{(1)x}{5x}\)

S gives K five plants. Account for it twice. The total quantities of both people have changed: \(\frac{x + 5}{5x - 5}\)

. . . and after S gives K the plants, the new ratio is 2:9

\(\frac{x + 5}{5x - 5}\) = \(\frac{2}{9}\)

10x - 10 = 7x + 35 3x = 45 x = 15 --> the multiplier for the original ratio quantities

So K had x = 15 plants And S had 5x = 75 plants

K now has 5 more = 20 S now has 5 fewer = 70

How many more plants does S have after five are given? 70 - 20 = 50