151. 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?

1. 1. 133	1
      	3

   
   
   

   2. 1

      200

   
   
   

   3. 72

   
   
   

   4. 66

   
   
   

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1. View Hint View Answer Discuss in Forum

   Weight of zinc
   

   = 200 ×	5	= 125 gram
   	8

   
   Weight of copper
   

   = 200 ×	3	= 75 gram
   	8

   
   Let the ratio of 125 gram zinc and x gram copper be 3 : 5
   

   ∴	125	=	3
   	x		5

   
   

   ∴  x =	125 × 5	=	625	gram
   	3		3

   
   ∴  Addition of copper in mixture
   

   =	625	− 75 =	625 − 225
   	3		3

   
   

   =	400	= 133	1	gram.
   	3		3

   Correct Option: A

   Weight of zinc
   

   = 200 ×	5	= 125 gram
   	8

   
   Weight of copper
   

   = 200 ×	3	= 75 gram
   	8

   
   Let the ratio of 125 gram zinc and x gram copper be 3 : 5
   

   ∴	125	=	3
   	x		5

   
   

   ∴  x =	125 × 5	=	625	gram
   	3		3

   
   ∴  Addition of copper in mixture
   

   =	625	− 75 =	625 − 225
   	3		3

   
   

   =	400	= 133	1	gram.
   	3		3

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152. The ratio of copper and zinc in brass is 13 : 7. How much zinc will be there in 100 kg of brass ?

1. 1. 20 kg.

   
   
   

   2. 55 kg.

   
   
   

   3. 35 kg.

   
   
   

   4. 40 kg.

   
   
   

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1. View Hint View Answer Discuss in Forum

   ∵  In 20 gm of brass, quantity of zinc = 7gm
   ∴  In 100 gm of brass, quantity
   of zinc = 7 × 5 = 35 gm.

   Correct Option: C

   ∵  In 20 gm of brass, quantity of zinc = 7gm
   ∴  In 100 gm of brass, quantity
   of zinc = 7 × 5 = 35 gm.

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153. The 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 be mixed to obtain a new mixture in vessel C containing half milk and half water ?

1. 1. 7 : 5

   
   
   

   2. 5 : 2

   
   
   

   3. 3 : 11

   
   
   

   4. 1 : 2

   
   
   

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1. View Hint View Answer Discuss in Forum

   By the rule of alligation,
   
   

   ∴  Required ratio =	1	:	1
   	10		14

   
   = 14 : 10 = 7 : 5

   Correct Option: A

   By the rule of alligation,
   
   

   ∴  Required ratio =	1	:	1
   	10		14

   
   = 14 : 10 = 7 : 5

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154. The ratio of spirit and water in two mixturers of 20 litre and 36 litre is 3 : 7 and 7 : 5 respectively. Both the mixtures are mixed together. Now the ratio of the spirit and water in the new mixture is

1. 1. 25 : 29

   
   
   

   2. 9 : 10

   
   
   

   3. 27 : 29

   
   
   

   4. 27 : 31

   
   
   

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1. View Hint View Answer Discuss in Forum

   In 20 litres of mixture,
   

   Spirit =	3	× 20 = 6 litres,
   	10

   
   Water = 14 litres
   In 36 litres of mixture
   

   Spirit =	7	× 36 = 21 litres
   	12

   
   Water = 15 litres
   ∴  Required ratio = (21 + 6) : (14 + 15)
   = 27 : 29

   Correct Option: C

   In 20 litres of mixture,
   

   Spirit =	3	× 20 = 6 litres,
   	10

   
   Water = 14 litres
   In 36 litres of mixture
   

   Spirit =	7	× 36 = 21 litres
   	12

   
   Water = 15 litres
   ∴  Required ratio = (21 + 6) : (14 + 15)
   = 27 : 29

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155. Two vessels contain milk and water in the ratio 3 : 2 and 7 : 3. Find the ratio in which the contents of the two vessels have to be mixed to get a new mixture in which the ratio of milk and water is 2 : 1.

1. 1. 2 : 1

   
   
   

   2. 1 : 2

   
   
   

   3. 4 : 1

   
   
   

   4. 1 : 4

   
   
   

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1. View Hint View Answer Discuss in Forum

   By Alligation Rule
   
   

   ∴  Required ratio =	1	:	1
   	30		15

   
   = 1 : 2

   Correct Option: B

   By Alligation Rule
   
   

   ∴  Required ratio =	1	:	1
   	30		15

   
   = 1 : 2

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