16.Milk and water in two vessels A and B are in the ratio 4 : 3 and 2 : 3 respectively.In what ratio the liquids in both the vessels should be mixed to obtsin anew mixture in vessel C, maintaining half milk and half water? A) 1 : 1 B) 7 : 5 C) 2 : 4 D) 1 : 3 View Answer Report DiscussAnswer: Option BExplanation:Let the quantities of liquids in vessels A and B mixed be, x litres and y litres respectively. $\frac{4}{7}x+\frac{2}{5}y=\frac{3}{7}x+\frac{3}{5}y$ $\Rightarrow \frac{x}{y}=\frac{7}{5}=7:5$
17.A mixture contains alcohol and water in the ratio 4 : 3.If 5 litres of water is added to the mixture, the ratio becomes 4 : 5.The quality of alcohol in the given mixture is A) 10 litres B) 12 litres C) 11 litres D) 15 litres View Answer Report DiscussAnswer: Option AExplanation:Let the quality of alcohol and water be 4x and 3xlitres respectively. Then, $\frac{4x}{3x+5}= \frac{4}{5} \Rightarrow20x=12x+20,x=25$ Quality of alcohol$=4x=4\times 2.5=10 litres$
18.Two equal glasses fillde with mixture of milk and water in the proportion of 2 : 1 and 1 : 1 respectively are emptied into a third glass.What is the proportion of milk and water in the third? A) 3 : 7 B) 5 : 7 C) 4 :7 D) 7 : 5 View Answer Report DiscussAnswer: Option DExplanation:Milk content in third glass $=\frac{2}{3} + \frac{1}{2}=\frac{7}{6}$ Water content in third glass $=\frac{1}{3}+\frac{1}{2}=\frac{5}{6}$ Ratio of milk and water $=\frac{7}{6} : \frac{5}{6}= 7 : 5$
19.A pot contains 81 litres of pure milk.$\frac{1}{3}$ of milk is replaced by the same amount of water.Again $\frac{1}{3}$ of the mixture is replaced by the same amount of water.Find the ratio of milk to water in the new mixture? A) 5 : 4 B) 4 : 5 C) 2 : 3 D) 3 : 2 View Answer Report DiscussAnswer: Option BExplanation:Amountof milk=81 l $\frac{1}{3}$ of whole milk $=\frac{81}{3}=27l$ Quality of milk left after first operation =81-27=54 Again amount of water $=\frac{54}{3}=18$ Quality of milk left after 2nd opertaion =54-18=36 Ratio of milk to water =36 ; (81-36) =36 : 45=4 : 5
20.180 kg of mixture of milk and water contains 5% water.How much more water should be added to it that water may be 10% in the mixture? A) 10 kg B) 15 kg C) 20 kg D) 12 kg View Answer Report DiscussAnswer: Option AExplanation:quality of water $=\frac{180\times 5}{100}=9kg$ Quality of milk $=180-9=171kgg$ Let x kg water be added.then, $\frac{9+x}{180+x}\times 100=10$ $90+10x=180+x,x=10$ Hence, 10 kg of water should be added.
