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.
A makes up 8 percent of solution R and 18 percent [#permalink]
14 Dec 2015, 06:12
Expert's post
00:00
Question Stats:
73% (01:34) correct
26% (01:03) wrong based on 15 sessions
By weight, liquid A makes up 8 percent of solution R and 18 percent of solution S. If 3 grams of solution R are mixed with 7 grams of solution S, then liquid A accounts for what percent of the weight of the resulting solution? A. 10% B. 13% C. 15% D. 19% E. 26%
Practice Questions Question: 9 Page: 152 Difficulty: medium
Re: A makes up 8 percent of solution R and 18 percent [#permalink]
14 Dec 2015, 06:19
Expert's post
Solution
Here we are mixing two solutions R and S. the percentages of A in the two solutions are 8% and 18% respectively. So the resultant mixture will also contain liquid A. and it will also depend on the weights of R and S
We can write that %A in mixture = \(\frac{(3 * 8% + 7 *18%)}{(3 +7)}\) the result is almost equal to 15%. Hence 15% is the right answer.
_________________
Sandy If you found this post useful, please let me know by pressing the Kudos Button
Re: A makes up 8 percent of solution R and 18 percent [#permalink]
14 Jul 2016, 08:22
I chose Answer C, but it was considered wrong!
sandy wrote:
Solution
Here we are mixing two solutions R and S. the percentages of A in the two solutions are 8% and 18% respectively. So the resultant mixture will also contain liquid A. and it will also depend on the weights of R and S
We can write that %A in mixture = \(\frac{(3 * 8% + 7 *18%)}{(3 +7)}\) the result is almost equal to 15%. Hence 15% is the right answer.
Re: A makes up 8 percent of solution R and 18 percent [#permalink]
01 Aug 2016, 10:51
sandy wrote:
By weight, liquid A makes up 8 percent of solution R and 18 percent of solution S. If 3 grams of solution R are mixed with 7 grams of solution S, then liquid A accounts for what percent of the weight of the resulting solution? A. 10% B. 13% C. 15% D. 19% E. 26%
Practice Questions Question: 9 Page: 152 Difficulty: medium
Why does it shows "E" as the correct answer,whereas,it should be "C". Answer is incorrect.
Re: A makes up 8 percent of solution R and 18 percent [#permalink]
11 Feb 2019, 11:14
Expert's post
sandy wrote:
By weight, liquid A makes up 8 percent of solution R and 18 percent of solution S. If 3 grams of solution R are mixed with 7 grams of solution S, then liquid A accounts for what percent of the weight of the resulting solution? A. 10% B. 13% C. 15% D. 19% E. 26%
When solving mixture questions, I often find it useful to sketch the solutions with the ingredients SEPARATED.
We have 3 grams of solution R, which is comprised of 8% liquid A So, 8% of the 3 grams will be liquid A 8% of 3 = (0.08)(3) = 0.24 So, solution R consists of 0.24 grams of liquid A
We'll now ADD 7 grams of solution S, which is comprised of 18% liquid A 18% of 7 = (0.18)(7) = 1.26 So, solution S consists of 1.26 grams of liquid A
Liquid A accounts for what percent of the weight of the resulting solution? When we combine the solutions BY PARTS, we get the following:
So, liquid A makes up 1.5 grams of the 10 grams in the resulting solution. 1.5/10 = 15/100 = 15%
Answer: C
Cheers, Brent
RELATED VIDEO FROM MY COURSE
_________________
Brent Hanneson – Creator of greenlighttestprep.com Sign up for our free GRE Question of the Dayemails
Re: A makes up 8 percent of solution R and 18 percent [#permalink]
11 Feb 2019, 11:20
Expert's post
sandy wrote:
By weight, liquid A makes up 8 percent of solution R and 18 percent of solution S. If 3 grams of solution R are mixed with 7 grams of solution S, then liquid A accounts for what percent of the weight of the resulting solution? A. 10% B. 13% C. 15% D. 19% E. 26%
Another approach is to use the Weighted Averages formula:
Weighted average of groups combined = (group A proportion)(group A average) + (group B proportion)(group B average) + (group C proportion)(group C average) + ...
The weight of the resulting solution is 10 grams (3 grams + 7 grams = 10 grams)
Solution R makes up 3/10 of the resulting solution. Solution R is comprised of 8% liquid A
Solution S makes up 7/10 of the resulting solution. Solution S is comprised of 18% liquid A
Apply the formula to get: % liquid A in final solution = (3/10)(8) + (7/10)(18) = 24/10 + 126/10 = 150/10 = 15%
Answer: C
Cheers, Brent
RELATED VIDEO FROM MY COURSE
_________________
Brent Hanneson – Creator of greenlighttestprep.com Sign up for our free GRE Question of the Dayemails
greprepclubot
Re: A makes up 8 percent of solution R and 18 percent
[#permalink]
11 Feb 2019, 11:20
close
73% (01:34) correct
