12 Days of Christmas GMAT Competition - Day 6: Solutions A, B, and C

Question

12 Days of Christmas GMAT Competition with Lots of Fun

Solutions A, B, and C are mixed. What is the ratio of alcohol and water in the resultant solution?

(1) A contains 20% alcohol, B contains 20% alcohol, and C contains 80% water.
(2) All solutions contain only water and alcohol.

Bunuel · Accepted Answer

Expert's Global Official Video Explanation

ogPqEpfTerQ

gmatophobia · Answer

Statement 1  :

We dont know if there are other constituents in the mixture. Hence this statement is not sufficient,

Statement 2  :
The only constituents are alcohol and water. However, the concentrations are not present hence not sufficient.

Combining both we get

Solution A - 20% alcohol & 80% water 
Solution B - 20% alcohol & 80% water 
Solution C - 20% alcohol & 80% water

Because the concentration of the constituents are same, the amount would not matter.

Hence C is sufficient.

IMO - C

mohitprabhat · Answer

Stmt 1 is insufficient since we don't know whether all solutions contain only water and alcohol.
Stmt 2 provides this information.

Hence, together they are sufficient. Ans-> C

behlmanmeet · Answer

Solutions A, B, and C are mixed. What is the ratio of alcohol and water in the resultant solution?

(1) A contains 20% alcohol, B contains 20% alcohol, and C contains 80% water.
(2) All solutions contain only water and alcohol.

Solution:

Statement 1: A contains 20% alcohol, B contains 20% alcohol, and C contains 80% water.

Now, we don't know what constitutes a solution. So, we can't gauge percentages of other substances in the solutions other than the given in the statement. So, if Alcohol is 20% in Sol A, we have no idea about the percentage of water.
statement 1 is insufficient.
 
 Statement 2: All solutions contain only water and alcohol. 
 Now, we know a solution has only water and alcohol. But we have no idea about their respective percentages.
Statement 2 is insufficient.

Statement 1+ Statement 2:

Let the volume of Sol A, B, and C be 100A, 100B, and 100C respectively.
So, alcohol in A= 20A, thus water in A=80A.
Similarly, alcohol in B= 20B, thus water in B=80B. Water in C=80C, thus alcohol in C= 20C.

The ratio of Alcohol and water in the final solution
Alcohol in final solution= 20(A+B+C)
Water in final solution= 80(A+B+C)
ratio=1:4

Thus, the answer is C.

poorvi125 · Answer

The ratios in which the three solutions are mixed isn't stated in either A or B.
Then how come C gives us the final ratio of Water to Alcohol?

Bunuel 
 ThatDudeKnows

ThatDudeKnows · Answer

A is 20% alcohol and 80% water.
B is 20% alcohol and 80% water.
C is 20% alcohol and 80% water.

Can you come up with a ratio of A:B:C that results in a total concentration that is different from 20% alcohol and 80% water?

12 Days of Christmas GMAT Competition - Day 6: Solutions A, B, and C

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards

GMAT Data Sufficiency (DS) Questions

12 Days of Christmas GMAT Competition - Day 6: Solutions A, B, and C

Prep Toolkit

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards