Problem Solving

AAPL wrote:A 75-liter solution of cool-drink is made from 8% jasmine water. If 3 liters of jasmine and 12 liters of water were added to the solution, what percent of the solution is jasmine?

A. 10.3%
B. 11.5%
C. 10%
D. 12.2%
E. 12%

The OA is C.

In 75 ltr volume of jasmine = 8/100 x 75 = 6ltr.
water = 75 - 6 = 69 ltr
adding 3 liters of jasmine and 12 liters of water .
total jasmine = 6 +3 = 9
total water = 69 + 15 = 84
total solution is 9 +84 = 93
% jasmine = (9/93) x 100 = 9.6% around 10%

Option C.

Has anyone another strategic approach to solve this PS question? Regards!

Your solution isn't quite correct.

A 75-liter solution of cool-drink is made from 8% jasmine water.
8% of 75 = (8/100)(75) = 6
So, the 75 liters is comprises of 6 liters of jasmine

If 3 liters of jasmine and 12 liters of water were added to the solution....
We adding 15 liters, so the NEW volume = 75 + 15 = 90 liters
The total volume of jasmine in the NEW mixture = 6 + 3 = 9

.. what percent of the solution is jasmine?....
9/90 = 1/10 = 10%

Answer: C

Cheers,
Brent

Hi All,

We're told that a 75-liter solution of cool-drink is made from 8% jasmine water and that 3 liters of jasmine and 12 liters of water were added to the solution. We're asked what percent of the new mixture is jasmine. This question can be solved as a Weighted Average.

To start, we have a 75 liter solution that is 8% jasmine. The 3 liters of jasmine and 12 liters of water can be mixed together to form....
a 15 liter solution that is 3/15 = 20% jasmine

At this point, it's worth noting that 75 is exactly '5 times' 15, so we can think of the final overall mixture as consisting of 6 "parts": 1 part that represents the 20% mixture and 5 parts that represent that 8% mixture. With a ratio of 1:5, we can set up a Weighted Averaged:

[(1)(20) + (5)(8)] / 6 = 60/6 = 10

Thus, the overall mixture will be 10% jasmine.

Final Answer: C

GMAT assassins aren't born, they're made,
Rich

AAPL wrote:A 75-liter solution of cool-drink is made from 8% jasmine water. If 3 liters of jasmine and 12 liters of water were added to the solution, what percent of the solution is jasmine?

A. 10.3%
B. 11.5%
C. 10%
D. 12.2%
E. 12%

We are given that a 75-liter solution is made from 8% jasmine water. Thus, the solution contains 75 x 0.08 = 6 liters of jasmine.

When 3 liters of jasmine and 12 liters of water are added to the solution, the percentage of solution that is jasmine is now:

(6 + 3)/(75 + 3 + 12) = 9/90 = 1/10 = 10%

Answer: C