101. In an alloy, the ratio of copper and zinc is 5 : 2. If 1.250 kg of zinc is mixed in 17 kg 500 g of
     alloy, then the ratio of copper and zinc will be

1. 1. 2 : 1

   
   
   

   2. 2 : 3

   
   
   

   3. 3 : 2

   
   
   

   4. 1 : 2

   
   
   

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1. View Hint View Answer Discuss in Forum

   Weight of copper in 17kg 500 gm i.e. 17500 gm of alloy
   

   =	5	× 17500 = 12500 gm
   	7

   
   Weight of zinc = (17500 – 12500)
   = 5000 gm
   1250 gm of zinc is mixed in alloy.
   ∴  Total weight of zinc
   = 1250 + 5000 = 6250 gm.
   ∴  Required ratio
   = 12500 : 6250 = 2 : 1

   Correct Option: A

   Weight of copper in 17kg 500 gm i.e. 17500 gm of alloy
   

   =	5	× 17500 = 12500 gm
   	7

   
   Weight of zinc = (17500 – 12500)
   = 5000 gm
   1250 gm of zinc is mixed in alloy.
   ∴  Total weight of zinc
   = 1250 + 5000 = 6250 gm.
   ∴  Required ratio
   = 12500 : 6250 = 2 : 1

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102. Four years ago, the ratio of A’s age to B’s age was 11 : 14 and four years later their age will be in the ratio 13 : 16. The present age of A is

1. 1. 48 years

   
   
   

   2. 26 years

   
   
   

   3. 44 years

   
   
   

   4. 28 years

   
   
   

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1. View Hint View Answer Discuss in Forum

   Let the age of A and B four years ago be 11x and 14x years respectively.
   According to the question,
   After 4 years from now,
   

   11x + 8	=	13
   14x + 8		16

   
   ⇒  176x + 128 = 182x + 104
   ⇒  182x – 176x = 128 – 104
   

   ⇒  6x = 24 ⇒ x =	24	= 4
   	6

   
   ∴  A’s present age = (11x + 4) years
   = 11 × 4 + 4 = 48 years

   Correct Option: A

   Let the age of A and B four years ago be 11x and 14x years respectively.
   According to the question,
   After 4 years from now,
   

   11x + 8	=	13
   14x + 8		16

   
   ⇒  176x + 128 = 182x + 104
   ⇒  182x – 176x = 128 – 104
   

   ⇒  6x = 24 ⇒ x =	24	= 4
   	6

   
   ∴  A’s present age = (11x + 4) years
   = 11 × 4 + 4 = 48 years

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103. If x : y = 3 : 4 and y : z = 3 : 4,
     

     then	x + y + z	is equal to
     	3z

1. 1. 13

      27

   
   
   

   2. 1

      2

   
   
   

   3. 73

      84

   
   
   

   4. 37

      48

   
   
   

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1. View Hint View Answer Discuss in Forum

   x : y = 3 : 4 = 9 : 12
   y : z = 3 : 4 = 12 : 16
   ∴  x : y : z = 9 : 12 : 16
   

   ∴	x + y + z	=	9k + 12k + 16k
   	3z		3 × 16k

   
   

   =	37
   	48

   Correct Option: D

   x : y = 3 : 4 = 9 : 12
   y : z = 3 : 4 = 12 : 16
   ∴  x : y : z = 9 : 12 : 16
   

   ∴	x + y + z	=	9k + 12k + 16k
   	3z		3 × 16k

   
   

   =	37
   	48

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104. A person distributes his pens among four friends A, B, C, D in the ratio
     

     =	1	:	1	:	1	:	1	What is the minimum number of pens
     	3		4		5		6

     that the person should have?

1. 1. 57

   
   
   

   2. 65

   
   
   

   3. 75

   
   
   

   4. 45

   
   
   

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1. View Hint View Answer Discuss in Forum

   A : B : C
   

   =	1	:	1	:	1	:	1
   	3		4		5		6

   
   

   =	1	× 60 :	1	× 60 :	1	× 60 :	1	× 60
   	3		4		5		6

   
   [LCM of 3, 4, 5 & 6 = 60]
   = 20 : 15 : 12 : 10
   ∴  Minimum number of pens
   = 20 + 15 + 12 + 10 = 57

   Correct Option: A

   A : B : C
   

   =	1	:	1	:	1	:	1
   	3		4		5		6

   
   

   =	1	× 60 :	1	× 60 :	1	× 60 :	1	× 60
   	3		4		5		6

   
   [LCM of 3, 4, 5 & 6 = 60]
   = 20 : 15 : 12 : 10
   ∴  Minimum number of pens
   = 20 + 15 + 12 + 10 = 57

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105. If	a	−	2	and	b	−	4
     	b		3		c		5

     then (a + b) : (b + c) = ?

1. 1. 3 : 4

   
   
   

   2. 4 : 5

   
   
   

   3. 5 : 9

   
   
   

   4. 20 : 27

   
   
   

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1. View Hint View Answer Discuss in Forum

   a : b = 2 : 3
   b : c = 4 : 5
   ∴  a : b : c = 2 × 4 : 3 × 4 : 3 × 5
   = 8 : 12 : 15
   

   ∴	a + b	=	8 + 12	=	20
   	b + c		12 + 15		27

   
   = 20 : 27

   Correct Option: D

   a : b = 2 : 3
   b : c = 4 : 5
   ∴  a : b : c = 2 × 4 : 3 × 4 : 3 × 5
   = 8 : 12 : 15
   

   ∴	a + b	=	8 + 12	=	20
   	b + c		12 + 15		27

   
   = 20 : 27

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