CAT 2018 Quant Questions

Question:
A 20% ethanol solution is mixed with another ethanol solution, say, S of unknown concentration in the proportion 1:3 by volume. This mixture is then mixed with an equal volume of 20% ethanol solution. If the resultant mixture is a 31.25% ethanol solution, then the unknown concentration of S is

52%
50%
55%
48%
Show Answer
Correct Answer: 2

Let the volume of the first and the second Solution be 100 and 300.

When they are mixed, quantity of ethanol in the mixture 

= (20 + 300S)

Let this Solution be mixed with equal volume i.e. 400 of third Solution in which the strength of ethanol is 20%.

So, the quantity of ethanol in the final Solution 

= (20 + 300S + 80) = (300S + 100)

It is given that, 31.25% of 800 = (300S + 100)

or, 300S + 100 = 250

or S = \(\frac{1}{2}\) = 50%

Hence, 50 is the correct answer.


Get one day FREE Trial of CAT online Full course FREE Registration
Also Check: 841+ CAT Quant Questions with Solutions


CAT Quant Online Course


  • 1000+ Practice Problems
  • Detailed Theory of Every Topics
  • Online Live Sessions for Doubt Clearing
  • All Problems with Video Solutions
₹ 2999

CAT 2018 Questions Paper with Solution PDF Download


CAT 2018 Quant Questions with Solutions

CAT 2018 Slot-1


CAT 2018 Slot-2


Back to Main Page


CAT 2018 Quant Questions
4.8 (96.47%) 17 votes