Directions: Each of the questions given below is followed by series of options among which you have to choose the best one. You can also review your choices by clicking into answer section.
16. Two containers A and B contain syrup and water in the ratio 7:5 and 3:1 respectively. In what ratio should they be mixed to obtain a new mixture containing syrup and water in the ratio 5:3?
A. 3:1
B. 2:1
C. 4:3
D. 7:5
Answer
Explanation:
No explanation
17. In what ratio must rice at Rs.9.30 per kg be mixed with rice at Rs.10.80 per kg so that the mixture is worth Rs.10 per kg?
A.7:8
B.31:36
C.8:7
D.36:31
Answer
Explanation:
By the rule of allegation (10.8 – 10): (10 – 9.3) = 0.8: 0.7 = 8 : 7
18. A jar contains 10 liters of milk. After selling 1 liter of milk, the milkman adds 1 liter of water to the jar. He repeats the process again. What is the percentage of milk contained in the jar now?
A. 81%
B. 82%
C. 72%
D. 80%
Answer
Explanation:
Amount of milk after 2 operations = 10[1-(1/10)]^2 = 10*(9/10)*(9/10) = 8.1 liters
% of milk = (8.1/10)*100 = 81%
19. A vessel is filled with liquid, 3 parts of which are water and 5 parts syrup. How much of the mixture must be drawn off and replaced with water so that the mixture may be half water and half syrup?
A.1/3
B.1/4
C.1/5
D.1/7
Answer
Explanation:
Suppose the vessel initially contains 8 liters of liquid.
Let x liters of this liquid be replaced with water.
Quantity of water in new mixture = 3 – (3x/8) + x liters
Quantity of syrup in new mixture = 5 – (5x/8) liters
3 – 3x/8 + x = 5 – 5x/8
5x + 24 = 40 – 5x
10x = 16
X = 8 /5
So, part of the mixture replaced = 8/5 x 1/8 = 1/5
20. Brand A costing Rs.9 per kg is mixed with brand B costing Rs.4 per kg to form a mixture worth Rs.7 per kg. How many kg of brand A are needed to make 40 kg of the mixture?
A. 12 kg
B. 15 kg
C. 18 kg
D. 24 kg
Answer
Explanation:
By the rule of allegation, 9 4 7 (7-4) : (9-7) 3:2 Brand A and B are mixed in the ratio of 3:2
To make 40 kg of the mixture, 40*3/5 = 24 kg of brand A are needed.
21. In what ratio must water be mixed with milk costing Rs.12 per liter in order to get a mixture worth of Rs.8 per liter?
A. 1 : 3
B. 2 : 2
C. 1 : 2
D. 3 : 1
Answer
Explanation:
By the rule of allegation, we have
Cost Price of 1 liter of water Cost Price of 1 liter of milk
0 12
Mean Price
8
12-8=4 8-0=8
Required Ratio = 4 : 8 = 1 : 2
22. To 15 liters of milk containing 20% water, 5 liters of pure milk is added. What is the % of water contained in the resulting mixture?
A. 18%
B. 16%
C. 15%
D. 25%
Answer
Explanation:
Amount of water present => 20% of 15 = 3 liters
After adding 5 liters of pure milk, 3 liters of water in 20 liters
% of water => (3/20)*100 = 15%
