391. If a : b : c = 2 : 3 : 4 and 2a –3b + 4c = 33, then the value of c is

1. 1. 6

   
   
   

   2. 9

   
   
   

   3. 12

   
   
   

   4. 66

      7

   
   
   

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1. View Hint View Answer Discuss in Forum

   a : b : c = 2 : 3 : 4
   

   ∴	a	=	b	=	c	= k (let)
   	2		3		4

   
   ⇒  a = 2k, b = 3k, and c = 4k
   Given 2a – 3b + 4c = 33
   ⇒  2 × 2k –3×3k + 4 ×4k = 33
   ⇒  4k –9k + 16k = 33
   

   ⇒  11k = 33 ⇒ k =	33	= 3
   	11

   
   ∴  c = 4k = 4×3 = 12

   Correct Option: C

   a : b : c = 2 : 3 : 4
   

   ∴	a	=	b	=	c	= k (let)
   	2		3		4

   
   ⇒  a = 2k, b = 3k, and c = 4k
   Given 2a – 3b + 4c = 33
   ⇒  2 × 2k –3×3k + 4 ×4k = 33
   ⇒  4k –9k + 16k = 33
   

   ⇒  11k = 33 ⇒ k =	33	= 3
   	11

   
   ∴  c = 4k = 4×3 = 12

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392. If a : b = c : d, then	ma + nc	is not equal to
     	mb + nd

1. 1. a

      b

   
   
   

   2. c

      d

   
   
   

   3. a + c

      b + d

   
   
   

   4. c − a

      b − d

   
   
   

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1. View Hint View Answer Discuss in Forum

   a : b = c : d
   

   ⇒	a	=	c	=	ma	=	nc
   	b		d		mb		nd

   
   

   ⇒	a + c	=	ma + nc
   	b + d		mb + nd

   Correct Option: C

   a : b = c : d
   

   ⇒	a	=	c	=	ma	=	nc
   	b		d		mb		nd

   
   

   ⇒	a + c	=	ma + nc
   	b + d		mb + nd

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393. The ratio of A to B is 4 : 5 and that of B to C is 2 : 3. If A equals 800, C equals

1. 1. 1000

   
   
   

   2. 1200

   
   
   

   3. 1500

   
   
   

   4. 2000

   
   
   

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1. View Hint View Answer Discuss in Forum

   A : B = 4 : 5
   B : C = 2 : 3
   ∴  A : B : C = 4 × 2 : 5 × 2 : 5 × 3
   = 8 : 10 : 15
   If A equals 800, then C equals 1500.

   Correct Option: C

   A : B = 4 : 5
   B : C = 2 : 3
   ∴  A : B : C = 4 × 2 : 5 × 2 : 5 × 3
   = 8 : 10 : 15
   If A equals 800, then C equals 1500.

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394. If a : b : c = 7 : 3 : 5, then (a + b + c) : (2a + b – c) is equal to

1. 1. 1 : 2

   
   
   

   2. 2 : 3

   
   
   

   3. 3 : 4

   
   
   

   4. 5 : 4

   
   
   

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1. View Hint View Answer Discuss in Forum

   a : b : c = 7 : 3 : 5
   

   ⇒	a	=	b	=	c	= k (let)
   	7		3		5

   
   ⇒  a = 7k, b = 3k, c = 5k
   Now (a + b + c) : (2a + b – c)
   = (7k + 3k + 5k) : (2 ×7k +3k –5k)
   = 15 k : 12 k = 5 : 4

   Correct Option: D

   a : b : c = 7 : 3 : 5
   

   ⇒	a	=	b	=	c	= k (let)
   	7		3		5

   
   ⇒  a = 7k, b = 3k, c = 5k
   Now (a + b + c) : (2a + b – c)
   = (7k + 3k + 5k) : (2 ×7k +3k –5k)
   = 15 k : 12 k = 5 : 4

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395. If A : B = 2 : 3 and B : C = 4 : 5, then A : B : C is

1. 1. 2 : 3 : 5

   
   
   

   2. 5 : 4 : 6

   
   
   

   3. 6 : 4 : 5

   
   
   

   4. 8 : 12 : 15

   
   
   

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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

   Correct Option: D

   A : B = 2 : 3
   B : C = 4 : 5
   ∴  A : B : C = 2 × 4 : 3 × 4 : 3 × 5
   = 8 : 12 : 15

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