Quantitative Aptitude – Arithmetic – Mixtures – A 20% ethanol solution is mixed


Quantitative Aptitude – Arithmetic - Mixtures – A 20% ethanol solution is mixed

Slot -2 – Quantitative Aptitude – Arithmetic – Mixtures – A 20% ethanol solution is mixed

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?

a) 55%
b) 52%
c) 48%
d) 50%

Answer: d) 50 %

Solution:
Let the volume of 20% ethanol solution in first mixtures = x so
Volume of S = 3x
Total volume of first solution = 4x
Total volume of final solution =2×4x=8x
Volume of ethanol solution in final mixture = x + 4x = 5x ,
So volume of S in final solution = 3x
Thus (31.25-20)/(s-31.25) = 3x/5x = 3/5
56.25=3s-93.75
3s=150
s=50%

Other posts related to Quantitative Aptitude – Modern Maths

Permutation and Combination – Fundamental Principle of Counting
Permutation and Combination – Distribution of Objects
How to find Rank of a Word in Dictionary (With or Without Repetition)
Set Theory- Maximum and Minimum Values
How to solve questions based on At least n in Set Theory for CAT Exam?
Sequence and Series Problems and Concepts for CAT 2017 Exam Preparation
Basic Probability Concepts for CAT Preparation

Crack CAT with Unacademy!

Use referral code HANDA to get 10% off.

  • Daily Live Classes
  • Live Tests and Quizzes
  • Structured Courses
  • Personalized Coaching