Quantitative Aptitude
ALLIGATION MCQs
Suppose the vessel initially contains 8 litres of liquid.
Let x litres of this liquid be replaced with water.
Quantity of water in new mixture = \(\left(3-\frac{3x}{8}+x\right) liters\)
Quantity of syrup in new mixture = \(\left(5-\frac{5x}{8}\right) liters\)
So, \(\left(3-\frac{3x}{8}+x\right)=\left(5-\frac{5x}{8}\right)\)
5x + 24 = 40 - 5x
10x = 16
x = \(\frac{8}{5}\)
So, part of the mixture replaced = \(\left(\frac{8}{5}\times\frac{1}{8}\right)=\frac{1}{5}\)
Since first and second varieties are mixed in equal proportions.
So, their average price = Rs. = Rs.130.50
So, the mixture is formed by mixing two varieties, one at Rs. 130.50 per kg and the other at say, Rs. x per kg in the ratio 2 : 2, i.e., 1 : 1. We have to find x.
By the rule of alligation, we have:
Cost of 1 kg of 1st kindCost of 1 kg tea of 2nd kind
Rs. 130.50
Mean Price
Rs. 153
Rs. x
(x - 153)
22.50
\(\frac{x-153}{22.50}=1\)
x - 153 = 22.50
Suppose the can initially contains 7x and 5x of mixtures A and B respectively
Quantity of A in mixture left = \(\left(7x-\frac{7}{12}\times9\right) liters=\left(7x-\frac{21}{4}\right) liters\)
Quantity of B in mixture left = \(\left(5-\frac{5}{12}\times9\right) liters=\left(5x-\frac{15}{4}\right) liters\)
So, \(\frac{\left(7x-\frac{21}{4}\right)}{\left(5x-\frac{15}{4}\right)+9}=\frac{7}{9}\)
\(\frac{28x-21}{20x+21}=\frac{7}{9}\)
252x - 189 = 140x + 147
112x = 336
x = 3.
So, the can contained 21 litres of A.
Let the cost of 1 litre milk be Re. 1
Milk in 1 litre mix. in 1st can = \(\frac{3}{4}\) litre, C.P. of 1 litre mix. in 1st can Re \(\frac{3}{4}\)
Milk in 1 litre mix. in 2nd can = \(\frac{1}{2}\) litre, C.P. of 1 litre mix. in 2nd can Re \(\frac{1}{2}\)
Milk in 1 litre of final mix.= \(\frac{5}{8}\) litre, Mean price = Re \(\frac{5}{8}\)
By the rule of alligation, we have:
C.P. of 1 litre mixture in 1st can = \(\frac{3}{4}\)
C.P. of mixture in 2nd can = \(\frac{1}{2}\)
Main price = \(\frac{5}{8}\)
So, Ratio of two mixtures = \(\frac{1}{8}:\frac{1}{8}=1:1\)
So, quantity of mixture taken from each can = \(\left(\frac{1}{2}\times12\right)= 6 litres\)
By the rule of alligation:
Cost of 1 kg pulses of 1st kind = Rs.15
Cost of 1 kg pulses of 2nd kind Rs.20
Main price = Rs. 16.50
So,Required rate = 3.50 : 1.50 = 7 : 3.
By the rule of alligation:
Cost of 1 kg pulses of 1st kind = Rs.15
Cost of 1 kg pulses of 2nd kind Rs.20
Main price = Rs. 16.50
So,Required rate = 3.50 : 1.50 = 7 : 3.
Let C.P. of 1 litre milk be Re. 1
Then, S.P. of 1 litre of mixture = Re. 1, Gain = 25%.
C.P. of 1 litre mixture = Re. \(\left(\frac{100}{125}\times1\right)=\frac{4}{5}\)
By the rule of alligation, we have:
C.P. of 1 litre of milk = Rs.1
C.P. of 1 litre of water = 0
So, Ratio of milk to water = \(\frac{4}{5}:\frac{1}{5}=4:1.\)
Hence, percentage of water in the mixture = \(\left(\frac{1}{5}\times100\right)\) % = 20%
S.P. of 1 kg of mixture = Rs. 9.24, Gain 10%.
So, C.P. of 1 kg of mixture = Rs. \(\left(\frac{100}{110}\times9.24\right)=Rs. 8.40\)
By the rule of allilation, we have:
C.P. of 1 kg sugar of 1st kind = Rs.9
Cost of 1 kg sugar of 2nd kind = Rs.7
Main Price = Rs. 8.40
So, Ratio of quantities of 1st and 2nd kind = 14 : 6 = 7 : 3.
Let x kg of sugar of 1st be mixed with 27 kg of 2nd kind.
Then, 7 : 3 = x : 27
x= \(\left(\frac{7\times27}{3}\right)= 63 kg.\)
Amount of milk left after 3 operations = \(\left[40\left(1-\frac{4}{140}\right)^{3}\right]litres\)
= \(\left(40\times\frac{9}{10}\times\frac{9}{10}\times\frac{9}{10}\right) =29.16 litres.\)
By the rule of alligation, we have:
Strength of first jar = 40%
Strength of 2nd jar = 19%
Main Strength = 26%
So, ratio of 1st and 2nd quantities = 7 : 14 = 1 : 2
So, Required quantity replaced = \(\frac{2}{3}\)
To solve this problem, let us first define some variables.
Let’s say,
Q = Quantity of whisky in the jar
%A = Percentage of alcohol in the jar
%B = Percentage of alcohol in the whisky replaced
We are given the following information:
Q = 1
%A = 40 %
%B = 19 %
Now, the task is to find the quantity of whisky replaced.
Now, using the formula for finding the percentage, we can write:
%A = (Quantity of whisky with 40% alcohol/Total Quantity of whisky)*100
%B = (Quantity of whisky with 19% alcohol/Total Quantity of whisky)*100
From the given information, we can write:
40% = (Q/Q)*100
19% = (Q2/Q)*100
Where Q2 is the quantity of whisky replaced with 19% alcohol.
Now, we need to find the value of Q2.
To do this, let us rearrange the equation to get:
Q2 = (19/40)*Q
Now, we need to find the value of Q.
To do this, let us rearrange the equation to get:
Q = (40/19)*Q2
Substituting the value of Q2 in the equation, we get:
Q = (40/19)*(19/40)*Q
Simplifying the equation, we get:
Q = (40/19)*Q
Dividing both the sides by Q, we get:
(40/19)*Q/Q = 1
Simplifying the equation, we get:
40/19 = 1
Now, we need to find the value of Q2.
Substituting the value of Q in the equation, we get:
Q2 = (19/40)*(40/19)*Q
Simplifying the equation, we get:
Q2 = Q
Therefore, the quantity of whisky replaced is equal to the total quantity of whisky in the jar.
Hence, the answer is Option B 2/3
If you think the solution is wrong then please provide your own solution below in the comments section .