Answer
Verified
460.8k+ views
Hint: We will be using the concepts of allegation and mixtures to solve the problem. We will also be using the traditional approach of solving word problems to make equations and solve them.
Complete step-by-step answer:
We have been given that a can contains a mixture of two liquids A and B in the ratio \[7:5\]. So, we will let the quantity of liquid \[\text{A = 7}x\] and \[\text{B = 5}x\].
Now, we have been given that 9 liters of amount of mixture are drawn off so the amount in which liquid A and B drawn off will be \[7:5\] and therefore the amount of A left and B left liquids are
Liquid A left \[\text{= 7}x-\dfrac{7\times 9}{12}\]
Now since B is filled after remaining 9L
Liquid B left \[\text{= 5}x-\dfrac{5\times 9}{12}+9\]
Now, we have been given that the ratio of liquid A and liquid B after the 9 liters of mixture are drawn off. So, we have the ratios as
\[\dfrac{\text{7}x-\dfrac{7\times 9}{12}}{5x-\dfrac{5\times 9}{12}+9}\ =\ \dfrac{7}{9}\]
\[\dfrac{\text{7}x-\dfrac{21}{4}}{5x-\dfrac{15}{4}+9}\ =\ \dfrac{7}{9}\]
We will cross-multiply and evaluate the expression to get x.
\[63x-\dfrac{21}{4}\times 9\ =\ 35x-\dfrac{15}{4}\times 7+63\]
\[28x\ =\ \dfrac{21}{4}\times 9-\dfrac{15}{4}\times 7+63\]
\[28x\ =\ \dfrac{189}{4}-\dfrac{105}{4}+63\]
\[28x\ =\ \dfrac{189-105}{4}+63\]
\[28x\ =\ \dfrac{84}{4}+63\]
\[28x\ =\ 21+63\]
\[28x\ =\ 84\]
\[x\ =\ \dfrac{84}{28}\]
\[x\ =\ 3\]
Now, since we have x, we can substitute this to find initial value of A. Therefore, initial value of \[\text{A}\ =\ 7\times 3\ =\ 21\ l\]
Hence option C is the correct answer.
Note: To solve this type of question it is important to note that the B has been filled after remaining 9L of mixture. So, it is understood that 9L of B has been added to fill up the container.
Complete step-by-step answer:
We have been given that a can contains a mixture of two liquids A and B in the ratio \[7:5\]. So, we will let the quantity of liquid \[\text{A = 7}x\] and \[\text{B = 5}x\].
Now, we have been given that 9 liters of amount of mixture are drawn off so the amount in which liquid A and B drawn off will be \[7:5\] and therefore the amount of A left and B left liquids are
Liquid A left \[\text{= 7}x-\dfrac{7\times 9}{12}\]
Now since B is filled after remaining 9L
Liquid B left \[\text{= 5}x-\dfrac{5\times 9}{12}+9\]
Now, we have been given that the ratio of liquid A and liquid B after the 9 liters of mixture are drawn off. So, we have the ratios as
\[\dfrac{\text{7}x-\dfrac{7\times 9}{12}}{5x-\dfrac{5\times 9}{12}+9}\ =\ \dfrac{7}{9}\]
\[\dfrac{\text{7}x-\dfrac{21}{4}}{5x-\dfrac{15}{4}+9}\ =\ \dfrac{7}{9}\]
We will cross-multiply and evaluate the expression to get x.
\[63x-\dfrac{21}{4}\times 9\ =\ 35x-\dfrac{15}{4}\times 7+63\]
\[28x\ =\ \dfrac{21}{4}\times 9-\dfrac{15}{4}\times 7+63\]
\[28x\ =\ \dfrac{189}{4}-\dfrac{105}{4}+63\]
\[28x\ =\ \dfrac{189-105}{4}+63\]
\[28x\ =\ \dfrac{84}{4}+63\]
\[28x\ =\ 21+63\]
\[28x\ =\ 84\]
\[x\ =\ \dfrac{84}{28}\]
\[x\ =\ 3\]
Now, since we have x, we can substitute this to find initial value of A. Therefore, initial value of \[\text{A}\ =\ 7\times 3\ =\ 21\ l\]
Hence option C is the correct answer.
Note: To solve this type of question it is important to note that the B has been filled after remaining 9L of mixture. So, it is understood that 9L of B has been added to fill up the container.
Recently Updated Pages
How many sigma and pi bonds are present in HCequiv class 11 chemistry CBSE
Mark and label the given geoinformation on the outline class 11 social science CBSE
When people say No pun intended what does that mea class 8 english CBSE
Name the states which share their boundary with Indias class 9 social science CBSE
Give an account of the Northern Plains of India class 9 social science CBSE
Change the following sentences into negative and interrogative class 10 english CBSE
Trending doubts
A group of fish is known as class 7 english CBSE
The highest dam in India is A Bhakra dam B Tehri dam class 10 social science CBSE
Write all prime numbers between 80 and 100 class 8 maths CBSE
Fill the blanks with the suitable prepositions 1 The class 9 english CBSE
Onam is the main festival of which state A Karnataka class 7 social science CBSE
Who administers the oath of office to the President class 10 social science CBSE
Differentiate between homogeneous and heterogeneous class 12 chemistry CBSE
Kolkata port is situated on the banks of river A Ganga class 9 social science CBSE
Difference between Prokaryotic cell and Eukaryotic class 11 biology CBSE