Question: 11 -

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 obtain a new mixture in vessel C containing half milk and half water?

 1:5

7:5

1:3

7:4

Answer:

7:5

Solution:

Milk in A=4/7 of whole milk in B=2/5 of whole milk in mixture A and B =1/2 of the whole. 


Let the C.P of unit quantity be Re.1 

Required ratio = 1/10 = 1/14 =14 : 10 =7: 5

Question: 12 -

A Container contains 192 liter of Milk. A seller draws out x% of Milk and replaced it with the same quantity of water. He repeated the same process for 3 times. And thus Milk content in the mixture is only 81 liter. Then how much percent he withdraw every time?

15%

25%

10%

18%

Answer:

25%

Solution:

81 = 192(1-x/100)³
x = 25

Question: 13 -

How much water must be added to a bucket which contains 40 liters of milk at the cost price of Rs.3.50 per liter so that the cost of milk reduces to Rs.2 per liter?

28 litres

35 liters

30 liters

25 liters

Answer:

30 liters

Solution:

Total cost price =Rs(40 x 7/2) = Rs.140 

Cost per litre =Rs.2, 
Total quantity = 140/2 = 70 Litres.  
Water to be added =(70-40) =30 Litres.

Question: 14 -

 In what proportion must water be added to spirit to gain 20% by selling it at the cost price?

4:5

3:5

2:5

1:5

Answer:

1:5

Solution:

Let the C.P be Re.1 per liter 


S.P of 1 litre of mix =Re 1, 

Gain = 20% 

C.P of 1 litre mix =Rs(100/120 x 1) =Re(5/6) 

Ratio of water and spirit = 1/6 =5/6 = 1 : 5.

Question: 15 -

A Jar contains 30 liters mixture of Milk and Water in the ratio of x:y respectively. When 10 liter of the mixture is taken out and replaced it water, then the ratio becomes 2:3. Then what is the initial quantity of Milk in the Jar?

15 Liter

20 Liter

12 Liter

18 Liter

Answer:

18 Liter

Solution:

x+y =30
(x-10*x/x+y)/ (y-10*y/(x+y) + 10) = 2/3
2x-4/3y = 20
x =18