Last visit was: 20 Nov 2024, 05:43 It is currently 20 Nov 2024, 05:43

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
Retired Moderator
Joined: 10 Apr 2015
Posts: 6218
Own Kudos [?]: 12193 [0]
Given Kudos: 136
Send PM
Manager
Manager
Joined: 06 Nov 2020
Posts: 85
Own Kudos [?]: 69 [0]
Given Kudos: 101
Send PM
Retired Moderator
Joined: 18 Oct 2018
Posts: 148
Own Kudos [?]: 182 [0]
Given Kudos: 27
Send PM
Retired Moderator
Joined: 10 Apr 2015
Posts: 6218
Own Kudos [?]: 12193 [0]
Given Kudos: 136
Send PM
Re: How many liters of a solution that is 15 percent salt must b [#permalink]
1
GreenlightTestPrep wrote:
How many liters of a solution that is 15 percent salt must be added to 5 liters of a solution that is 8 percent salt so that the resulting solution is 10 percent salt?

Show: ::
2


When solving mixture questions, it can be useful to sketch the solutions with the ingredients SEPARATED.
8% of 5 liters = 0.4 liters. So, the original mixture contains 0.4 liters of salt

Let x = the volume (in liters) of 15% solution required
So, this solution contains 0.15x liters of salt

We get:
Image

We want the resulting solution to be 10% salt.

In other words, we want: \(\frac{0.4 + 0.15x}{5+x}=\frac{10}{100}\) (aka 10%)

Simplify: \(\frac{0.4 + 0.15x}{5+x}=\frac{1}{10}\)

Cross multiply: \((10)(0.4 + 0.15x) = 5+x\)

Expand: \(4 + 1.5x = 5+x\)

Solve: \(x = 2\)

Answer: 2

Cheers,
Brent
Prep Club for GRE Bot
Re: How many liters of a solution that is 15 percent salt must b [#permalink]
Moderators:
GRE Instructor
78 posts
GRE Forum Moderator
37 posts
Moderator
1111 posts
GRE Instructor
234 posts

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