Alligation or Mixture - Quantitative Aptitude (MCQ) questions

1)   In what proportion must wheat at Rs. 15 per kg. be mixed with wheat at Rs. 18 per kg. So that the mixture will be worth Rs. 17 per kg. ?
- Published on 19 Apr 16

a. 2 : 1
b. 1 : 2
c. 3 : 2
d. 2 : 3
Answer  Explanation 

ANSWER: 1 : 2

Explanation:
Wheat/Rs. 15 per kg.
Wheat/Rs. 18 per kg.
For the mixture to be worth Rs. 17 per kg. The ratio should be:
(18 – 17) : (17 – 15)
1 : 2


2)   If 500 gm of salt solution has 30% salt in it, how much salt must be added to make the concentration of salt 50% in the solution?
- Published on 07 Apr 16

a. 200 gm
b. 100 gm
c. 90 gm
d. 50 gm
e. None of these
Answer  Explanation 

ANSWER: 200 gm

Explanation:
Amount of water in solution = 100 % - 30 % = 70 % of total
Amount of water = 70 % x 500 = 350 gm
Amount of water remains same for both the solutions. Therefore, let amount of new solution be x gm.
x = 350 x (100/ 50)
x = 700
Salt added = (700 – 500) = 200 gm

Alternate solution:

Quantity of sugar to be added :
= [Solution (Required % value – Present % value)] / (100 – Required % value)
= [500 (50 – 30)] / 100 – 50
= (500 x 20) / 50
= 200 gm


3)   To gain profit, a milkman adds 1.5 litre of water to a certain amount of milk. He sells the adulterated milk at Rs.28 per litre and pure milk costs Rs.36 per litre. Find the amount of milk.
- Published on 06 Jul 15

a. 5.25
b. 6
c. 5.5
d. 5
Answer  Explanation 

ANSWER: 5.25

Explanation:
Let the amount of milk be x.
36x = 28(x + 1.5)
36x = 28x + 42
8x = 42
x = 5.25 litres


4)   A tank of 100 litres is filled with kerosene. Ram replaces 10% of kerosene with water and repeats this procedure 4 times. What is the amount of kerosene left in the tank?
- Published on 06 Jul 15

a. 60 litres
b. 65.61 litres
c. 70 litres
d. 65 litres
Answer  Explanation 

ANSWER: 65.61 litres

Explanation:
As Ram replaces 10% of kerosene with water, the amount of kerosene left is 90%.
As the replacement is done four times,
After 1st replacement, kerosene left is : 0.9*100 = 90 litres
After 2nd replacement, kerosene left is : 0.9*90 = 81 litres
After 3rd replacement, kerosene left is : 0.9*81 = 72.9 litres
After 4th replacement, kerosene left is : 0.9*72.9 = 65.61 litres


5)   An empty bottle weighs 1/6th of the full bottle. When a certain percent of water was removed and the bottle was weighed, the weight of the bottle turned out to be 1/3rd of the bottle when it was full. What is the percent of water removed?
- Published on 06 Jul 15

a. 70%
b. 85%
c. 80%
d. 75%
Answer  Explanation 

ANSWER: 80%

Explanation:
Let the weight of full bottle be 6kg.
Therefore, weight of empty bottle is 1kg and that of water is 5kg.
If x% of water is removed, the weight of the bottle becomes 2kg.
Therefore, the amount of water removed is 4kg.
% of water removed = 4/5 *100 = 80%


6)   A container contains 30 liters of milk. From this container 5 liter of milk was taken out and replaced by water. This process was repeated further two times. How much milk is now contained by the container?

- Published on 06 Jul 15

a. 18.45 liter
b. 23.44 liter
c. 17.36 liter
d. 21.87 liter
Answer  Explanation 

ANSWER: 17.36 liter

Explanation:
No explanation is available for this question!


7)   A container contains 30 liters of milk. From this container 5 liter of milk was taken out and replaced by water. This process was repeated further two times. How much milk is now contained by the container?
- Published on 06 Jul 15

a. 18.45 liter
b. 23.44 liter
c. 17.36 liter
d. 21.87 liter
Answer  Explanation 

ANSWER: 17.36 liter

Explanation:
No explanation is available for this question!


8)   Find the ratio in which wheat of inferior quality (Rs.14/kg) be mixed with wheat of superior quality (Rs.28/kg) so that the shopkeeper gains Rs.2 by selling the resulting mixture at Rs.20/kg.

- Published on 06 Jul 15

a. 1 : 3
b. 5 : 2
c. 3 : 4
d. 2 : 5
Answer  Explanation 

ANSWER: 5 : 2

Explanation:
Let the resulting mixture be 1 kg, and x kg be the amount of wheat of inferior quality.
Therefore, (1-x)kg is the amount of wheat of superior quality.
As the shopkeeper gains Rs.2, the cost of the mixture is Rs.18
14*x + 28*(1-x) = 18
14x - 28x + 28 = 18
14x = 10
x = 5/7
(1 – x) = 2/7
x : (1-x) = 5/7 : 2/7
= 5 : 2


9)   Vessel ‘A’ contains 150 litres of mixture of milk and water in the ratio of 3:1. Vessel ‘B’ contains 200 litres of the mixture in the ratio of 5:2. If the mixture from both the vessels are poured into vessel ‘C’, find the ratio of the resulting mixture.
- Published on 06 Jul 15

a. 15 : 7
b. 8 : 3
c. 15 : 2
d. 143 : 53
Answer  Explanation 

ANSWER: 143 : 53

Explanation:
As vessel A contains 150 litres of mixture of milk and water in the ratio 3:1, the quantity of milk is 3*150/4 litres, and that of water is 150/4 litres.
Similarly, as vessel B contains 200 litres of mixture of milk and water in the ratio 5:2, the quantity of milk is 5*200/7, and that of water is 2*200/7 litres.
After mixing the total quantity is 350 litres.
The quantity of milk is {(3*150/4) + (5*200/7)} = 7150/28
The quantity of water is {(150/4) + (2*200/7)} = 2650/28
The ratio of the resulting mixture = 7150/2650 = 143 : 53


10)   A jar is filled of liquid which is 3 parts water and 5 parts alcohol. How much of this mixture should be drawn out and replaced such that this mixture may contain half
water and half alcohol?

- Published on 15 Jun 15

a. 25%
b. 20%
c. 14.29%
d. 33.33%
Answer  Explanation 

ANSWER: 20%

Explanation:
Let the jar initially contain 8 litres of mixture:3 litres water and 5 litres alcohol

Let x litres of this mixture is drawn out and is replaced by x litres of water.

Amount of water now in the solution: 3-(3/8)x+x.

Amount of alcohol now in the solution: 5-(5/8)x

Desired ratio: 1/1

=>3-(3/8)x+x=5-(5/8)x

x=8/5 litres

%x=((8/5)/8)*100=20%


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