# SBI Clerk Prelims 2016- Practice Aptitude Questions (Allegation& Mixture)

SBI Clerk 2016- Practice Aptitude Questions (Allegation& Mixture) Set-18:
Dear Readers, Important Practice Aptitude Questions with solution for Upcoming SBI Clerk Exam, candidates those who are preparing for those exams can use this practice questions.
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1).In a 25 litres mixture of spirit and water, there is only 50% spirit. 5 litres of this mixture is taken out and 5 litres of pure water is added to the remaining mixture. Find the percentage of water in the final mixture
a)Â Â 60%
b)Â Â 75%
c)Â Â 50%
d)Â Â 40%
e)Â Â None of these
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2).A painter mixes blue paint with white paint so that the mixture contains 10% blue paint. In a mixture of 40 litres paint how many litres of blue paint should be added so that the mixture contains 20% of blue paint ?
a)Â Â 2.5 litres
b)Â Â 4 litres
c)Â Â 5 litres
d)Â Â 2 litres
e)Â Â None of these
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3).A container contains 10 litres mixture in which there is 10% sulphuric acid. How much sulphuric acid is to be added to make the solution contain 25% sulphuric acid ?
a)Â Â 2 litres
b)Â Â 1 litres
c)Â Â 4 litres
e)Â Â None of these
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4).What quantity of water should be added to 3 litres of 10% solution of salt, so that it becomes a 5% salt solution ?
a)Â Â 1.5 litres
b)Â Â 2.7 litres
c)Â Â 3 litres
d)Â Â Cannot be determined
e)Â Â None of these
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5).The wheat sold by a grocer contained 10% low quality wheat. What quantity of good quality wheat should be added to 150 kg of wheat so that the percentage of low quality wheat becomes 5%?
a)Â Â 150 kg
b)Â Â 135 kg
c)Â Â 50 kg
d)Â Â 85 kg
e)Â Â None of these
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6).Zinc and copper are in the ratio of 5 : 3 in 200 gm of an alloy. How much grams of copper be added to make the ratio as 3 : 5 ?
a)Â Â 133(1 / 3)gm
b)Â Â 1 / 200 gm
c)Â Â 72 gm
d)Â Â 66 gm
e)Â Â None of these
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7).1 litre of water, is added to 5 litres of alcohol water solution containing 40% alcohol strength. The strength of alcohol in the new solution will be
a)Â Â 30%
b)Â Â 33%
c)Â Â 33(2 / 3)%
d)Â Â 33(1 / 3)%
e)Â Â None of these
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8).The milk and water in a mixture are in the ratio 7 : 5. When 15 litres of water is added to it, the ratio of milk and water in the new mixture becomes 7 : 8. The total quantity of water in the new mixture is
a)Â Â 35 litres
b)Â Â 40 litres
c)Â Â 60 litres
d)Â Â 96 litres
e)Â Â None of these
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9).In a 45 litres mixture of milk and water, the ratio of the milk to water is 2 : 1. When some quantity of water is added to the mixture, this ratio becomes 1 : 2. The quantity of water added is
a)Â Â 10 litres
b)Â Â 21 litres
c)Â Â 35 litres
d)Â Â 45 litres
e)Â Â None of these
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10).A mixture of 30 litres contains milk and water in the ratio of 7 : 3. How much water should be added to it so that the ratio of milk and water becomes 3 : 7?
a)Â Â 40 litres
b)Â Â 49 litres
c)Â Â 56 litres
d)Â Â 63 litres
e)Â Â None of these
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Answers:Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â
1).a) 2).c) 3).a) 4).c) 5).a) 6).a) 7).d) 8).b) 9).d) 10).a)
Solution:
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1).Concentration of water is 50% in mixture and 100% in water

[We have 20 litres of mixture and 5 litres of water]
(100 â€“ x) / (x â€“ 50) = 4 / 1
(100 â€“ x) = (4x â€“ 200)
300 = 5x
x = 60%
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2).

Ratio = 80 : 10 or 8 : 1
In 40 litres of mixture, 5 litres of blue paint must be mixed, Ratio becomes 40 : 5 or 8 : 1
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3).

Ratio = 75 : 15 = 5 : 1
In 10 litres of mixture, 2 litres of sulphuric acid must be added
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4).

Ratio = 5 : 5 = 1 : 1
Hence, in 3 litres of solution, 3 litres of water must be added.
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5).% of low quality wheat in first mixture = 10%

% of low quality wheat in good quality wheat (to be added) = 0%

Ratio = 5 : 5 = 1 : 1
Hence, in 150 kg of given mixture, 150kg of good quality wheat must be added.
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6).Fraction of copper in given mixture = 3 / 8

Fraction of cooper in copper = 1

Ratio = (3 / 8) : (2 / 8) = 3 : 2
In 200 gm of alloy, copper that should be added is calculated as, (3/5)x = 200
x = 200 Ã— (5 / 3) and copper
= 200 Ã— (5 / 3) Ã— (2 / 5)
= 400 / 3 = 133(1 / 3) gm
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7).In water, there is 0% alcohol and in mixture there is 40% alcohol

[(40 â€“ x) / (x â€“ 0)] = 1 / 5
200 -5x = x
x = 200 / 6 = 33(2 / 6)% = 33(1 / 3)%
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8).Concentration of water in initial mixture = 1/5
Concentration of water in water = 1

Concentration of water in final mixture =Â 8/15

Ratio = (7 / 15) : (7 / 60) = 4 : 1
Thus, 15 litres of water is added in 60 litres of initial mixture. Quantity of water in final mixture = 60(5 / 12) + 15 = 40 litres
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9).Consider concentration of water only

Ratio = (1 / 3) : (1 / 3) = 1 : 1
Hence, in 45 litres of mixture 45 litres of water is added.