If 50% of 2:3 solution of milk and water is replaced with water, then the concentration of the solution is reduced by
A)25
B)33
C)50
D)75

Answer – B)33
Explanation :
Milk : water
20 30
-10 -15
+25
—- —-
10 40
Concentration of solution reduced by 10 i.e. 50% and dilution increased by 40 i.e. 33.33%

Milk and water are in the ratio of 3:2 in a mixture of 80 liters. How much water should be added so that the rate of milk and water become 2:3?
A)25
B)40
C)35
D)20

How much water must be added to 100cc of 80% solution of Boric acid to reduce it to a 50% solution?
A)30
B)40
C)50
D)60

Answer – D)60
Explanation :50%(100+x)=80

In what proportion must a grocer mix one kind of bajra at Rs.4.50 per kg with another at Rs.4 per kg in order that by selling the mixture at Rs.5.20 per kg he may make a profit of 20%?
A)1:2
B)2:1
C)1:1
D)3:1

Answer – A)1:2
Explanation :
Mean Price= C.P. of per kg mixture=100/120 ×5.20 = R.s 4.333
By Allegation rule
4 4.5
…….4.333………
0.167 0.333

Milk and water are mixed in the vessels A and B in the ratios 5:2 and 8:5 respectively. In what proportion should quantities be taken from the two vessels so as to form a mixture containing milk and water in the ratio 9:4?
A)7:2
B)5:2
C)2:7
D)1:7

Answer – A)7:2
Explanation :
In A C.P. of 1 liter milk Rs5/7 and that of B= Rs8/13, mixture= Rs9/13
5/7 8/13
……9/13….
1/13 2/91

How must a shop owner mix 4 types of rice worth Rs95, Rs60, Rs90 and Rs50 per kg so that he can make the mixture of these rice worth Rs80 per kg?
A)3:2:4:6
B)2:3:6:4
C)1:5:3:6
D)6:4:3:2

Answer – A)3:2:4:6

A container contains 40 liters of the milk. From the container 4 liters of the milk was taken out and replaced by water. This process was repeated further two times. How much milk is now contained by the container?
A)29.61 liters
B)30.16 liters
C)29.16 liters
D)13.16 liters

Answer –C)29.16 liters
Explanation :
Amount of milk left after 3 operations
40(1-4/40) ^3 liters

A dairy man pays Rs.6.40 per liter of milk. He adds water and sells the mixture at Rs.8 per liter thereby making 37.5% profit. Find the ratio of the water to milk received by the customers?
A)1:15
B)1:20
C)1:12
D)1:10

Answer – D)1:10
Explanation :
Suppose milk x and water y liters
Reqd. ratio of water and milk= y:x
CP of x liters milk=Rs.6.4x
SP of x liters milk=Rs.8(x+y)
64=8(x+y)*100/137.5
X:y=1:10