316. A policeman starts to chase a thief. When the thief goes 10 steps the policeman moves 8 steps. 5 steps of the policeman is equal to 7 steps of the thief. The ratio of the speeds of the policeman and the thief is

1. 1. 25 : 28

   
   
   

   2. 25 : 26

   
   
   

   3. 28 : 25

   
   
   

   4. 56 : 25

   
   
   

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1. View Hint View Answer Discuss in Forum

   5 steps of policeman = 7 steps of thief
   

   ∴  8 steps of policeman =	7	× 8
   	5

   
   

   =	56	steps of thief
   	5

   
   

   ∴  Required ratio =	56	: 10
   	5

   
   = 56 : 50
   = 28 : 25

   Correct Option: C

   5 steps of policeman = 7 steps of thief
   

   ∴  8 steps of policeman =	7	× 8
   	5

   
   

   =	56	steps of thief
   	5

   
   

   ∴  Required ratio =	56	: 10
   	5

   
   = 56 : 50
   = 28 : 25

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317. In a school, 10% of number of girls is equal to (1/20)th of number of boys. Ratio between the number of boys to number of girls is

1. 1. 1 : 2

   
   
   

   2. 2 : 1

   
   
   

   3. 1 : 4

   
   
   

   4. 4 : 1

   
   
   

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1. View Hint View Answer Discuss in Forum

   If boys = x and girls = y, then
   

   y ×	10	=	x	⇒	y	=	x
   	100		20		10		20

   
   

   ⇒	x	=	20	=	2	= 2 : 1
   	y		10		1

   Correct Option: B

   If boys = x and girls = y, then
   

   y ×	10	=	x	⇒	y	=	x
   	100		20		10		20

   
   

   ⇒	x	=	20	=	2	= 2 : 1
   	y		10		1

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318. Two numbers are such that the square of one is 224 less than 8 times the square of the other. If the numbers are in the ratio of 3 :4, then their values are

1. 1. 12, 16

   
   
   

   2. 6, 8

   
   
   

   3. 9, 12

   
   
   

   4. 12, 9

   
   
   

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1. View Hint View Answer Discuss in Forum

   Numbers = 3x and 4x
   ∴  (4x)² = 8 × (3x)² – 224
   ⇒  16x² = 72x² – 224
   ⇒  72x² – 16x² = 224
   

   ⇒  56x2 = 224 ⇒ x2 =	224	= 4
   	56

   
   ⇒  x = √4 = 2
   ∴  Numbers = 6 and 8

   Correct Option: B

   Numbers = 3x and 4x
   ∴  (4x)² = 8 × (3x)² – 224
   ⇒  16x² = 72x² – 224
   ⇒  72x² – 16x² = 224
   

   ⇒  56x2 = 224 ⇒ x2 =	224	= 4
   	56

   
   ⇒  x = √4 = 2
   ∴  Numbers = 6 and 8

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319. A box filled with paper bundles weighs 36 kg. If the weight of the box and paper bundles respectively are in the ratio of 3 : 22, then the weight of the papers (in grams) is

1. 1. 30680 grams

   
   
   

   2. 30710 grams

   
   
   

   3. 31500 grams

   
   
   

   4. 31680 grams

   
   
   

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1. View Hint View Answer Discuss in Forum

   Weight of paper bundles =		22	× 36		kg
   		25

   
   

   =		22 × 36 × 1000		gm
   		25

   
   = 31680 gm

   Correct Option: D

   Weight of paper bundles =		22	× 36		kg
   		25

   
   

   =		22 × 36 × 1000		gm
   		25

   
   = 31680 gm

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320. The ratio of successful and unsuccessful examinees in an examination in a school is 6 : 1. The ratio would have been 9 : 1 if 6 more examinees had been successful. The total number of examinees is

1. 1. 140

   
   
   

   2. 120

   
   
   

   3. 200

   
   
   

   4. 160

   
   
   

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1. View Hint View Answer Discuss in Forum

   Total students = 6x + x = 7x
   

   ∴	6x + x	=	9
   	x − 6		1

   
   ⇒  6x + 6 = 9x– 54
   ⇒  9x – 6x = 54 + 6 = 60
   ⇒  3x = 60 ⇒ x = 20
   ∴  Total number of students
   = 7 × 20 = 140

   Correct Option: A

   Total students = 6x + x = 7x
   

   ∴	6x + x	=	9
   	x − 6		1

   
   ⇒  6x + 6 = 9x– 54
   ⇒  9x – 6x = 54 + 6 = 60
   ⇒  3x = 60 ⇒ x = 20
   ∴  Total number of students
   = 7 × 20 = 140

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