Answer: 65.61 litres

Explanation:
As Ram replaces 10% of kerosene with water, the amount of kerosene left is 90%.
As the replacement is done four times,
After 1st replacement, kerosene left is : 0.9*100 = 90 litres
After 2nd replacement, kerosene left is : 0.9*90 = 81 litres
After 3rd replacement, kerosene left is : 0.9*81 = 72.9 litres
After 4th replacement, kerosene left is : 0.9*72.9 = 65.61 litres

Answer: 3 : 2

Explanation:

Answer: Rs 8 and Rs 12

Explanation:
SP of mixture = 12.25
CP of mixture = 12.25(100/116 2/3) = 10.50
Let the CP of the two liquids be Rs x and Rs x+4 respectively

Price liquid1=x+4, liquid2=x
Resultant = 10.5

Proportion 10.5-x : x-6.5

(10.5 - x)/(x – 6.5) = 5/3 =>x=8
Prices of the two liquids = Rs 8 and Rs 12

Answer: ¹/3 part

Explanation:
The mixture contains ¾ part milk and ¼ part water
Let quantity of mixture withdrawn be x
Quantity of milk in the new mixture = ¾ - 3x/4
Quantity of water in the new mixture = ¼ - x/4 + x
¾ - 3x/4 = ¼ - x/4 + x =>x=1/3
1/3 part of the mixture should be withdrawn

Answer: 20%

Explanation:

Answer: 401 : 544

Explanation:
Let the volumes of all the glasses be 10 liters
Glass1 Spirit= 4 ,Water = 6, Total= 10
Glass2 Spirit= 30/7 ,Water = 40/7, Total= 10
Glass3 Spirit= 40/9 ,Water = 50/9, Total= 10

Mixture Spirit= 802/63 ,Water = 1088/63, Total= 30

Spirit : Water = 803 : 1088 = 401 : 544

Answer: 189kg

Explanation:
S.P = Rs. 6.6/kg.
SP = 110 CP / 100 => CP = (6.6 * 100)/110 = Rs. 6 = Mean Price
Rs. 4.50 / kg                                     Rs. 8 / kg
                              
                                  [6]

(8-6)                                                  (6 – 4.5)
Rs. 2 / kg                                          Rs. 1.50 / kg

Quantity of dearer / Quantity of cheaper = 1.5/2
Quantity of dearer = 252 x 1.5/2 = 126 x 1.5 = 189 kg.

Answer: 90.5%

Explanation:
Quantity of Tin Alloy1=10 and Alloy2=4
Quantity of Mixture 9
Proportion 5:1
The two alloys should be mixed in the ratio 5:1
Amount of copper in the mixture = 5(90/100)+1(93/100) = 5.43
% of copper in the mixture = [5.43/(5+1)]100= 90.5%

Answer: 7 : 3

Explanation:
By the rule of alligation:
Cost of 1 kg food grain of 1st kind Cost of 1 kg food grain of 2nd kind

Rs. 15                         Mean Price                   Rs. 20
3.50                             Rs. 16.50                      1.50

Required rate = 3.50 : 1.50 = 7 : 3

Answer: 2/3

Explanation:
Alloy1 silver=5,Copper = 1
Alloy2 silver=7,Copper = 2

Quantity of silver in alloy1=5/6
Quantity of silver in alloy2=7/9


Quantity of silver in Mixture=80/100=4/5

Proportion 1/45 : 1/30
The two alloys should be mixed in the ratio (1/45)/(1/30) = 2/3