516. A shopman bought pens at the rate of 7 for $ 10 and sold them at a profit of 40%. How many pens would a customer get for $ 10?

1. 1. 6

   
   
   

   2. 4

   
   
   

   3. 5

   
   
   

   4. 3

   
   
   

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1. View Hint View Answer Discuss in Forum

   Here , C.P. of 7 pens = $ 10
   On profit 40% ,
   

   S.P. of 7 pens =	10 × 140	= $ 14
   	100

   
   

   ∴ S.P. of 1 pen =	14	= $ 2
   	7

   
   Clearly, 5 pens were sold for $ 10
   Second method to solve this question :
   Here, a = 7, p = 10 and b = ?, q = 10, Gain% = 40%
   

   Gain % =		aq - bp			× 100%
   		bp

   
   

   Correct Option: C

   Here , C.P. of 7 pens = $ 10
   On profit 40% ,
   

   S.P. of 7 pens =	10 × 140	= $ 14
   	100

   
   

   ∴ S.P. of 1 pen =	14	= $ 2
   	7

   
   Clearly, 5 pens were sold for $ 10
   Second method to solve this question :
   Here, a = 7, p = 10 and b = ?, q = 10, Gain% = 40%
   

   Gain % =		aq - bp			× 100%
   		bp

   
   

   40 =			7 × 10 - b × 10			× 100%
   			b × 10

   
   ⇒ 4b = 70 – 10b
   ⇒ 14b = 70
   

   b =	70	b = 5
   	14

   
   

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517. By selling an article at (2 / 3) of the marked price, there is a loss of 10%. The profit per cent, when the article is sold at the marked price, is
     

1. 1. 20%

   
   
   

   2. 30%

   
   
   

   3. 35%

   
   
   

   4. 40%

   
   
   

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1. View Hint View Answer Discuss in Forum

   Suppose marked price = $ x
   

   ∴ S.P. = $	2x
   	3

   
   

   C.P. =		2x	× 100 =	20x
   		3 × 90		27

   
   

   Profit at marked price = x -		20x	=	7x
   		27		27

   
   

   Correct Option: C

   Suppose marked price = $ x
   

   ∴ S.P. = $	2x
   	3

   
   

   C.P. =		2x	× 100 =	20x
   		3 × 90		27

   
   

   Profit at marked price = x -		20x	=	7x
   		27		27

   
   
   

   =		7x	×	27	× 100 = 35%
   		27		20x

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518. If the sales tax be reduced from (7 / 2 )% to (10 / 3) % , what difference does it make to a person who purchases an article whose marked price is $ 8,400?

1. 1. $ 20

   
   
   

   2. $ 15

   
   
   

   3. $ 14

   
   
   

   4. $ 10

   
   
   

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1. View Hint View Answer Discuss in Forum

   Given that , marked price = $ 8,400
   

   Difference in percentage of sales tax =		7	-	10	=	21 - 20	=	1	%
   		2		3		6		6

   
   

   ∴ Required difference =	1	% of 8400
   	6

   
   

   Correct Option: C

   Given that , marked price = $ 8,400
   

   Difference in percentage of sales tax =		7	-	10	=	21 - 20	=	1	%
   		2		3		6		6

   
   

   ∴ Required difference =	1	% of 8400
   	6

   
   

   Required difference =		1	×	1	× 8400 = $ 14
   		6		100

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519. After selling 5% of a quantity of sugar, 5 kg. of sugar remains. Find the total quantity of sugar.

1. 1. 19 kg.

   
   
   

   2. 5	5	kg.
      	19

   
   
   

   3. 100 kg.

   
   
   

   4. 95 kg.

   
   
   

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1. View Hint View Answer Discuss in Forum

   Let the total quantity of sugar be y kg.
   According to the question,
   (100 – 5)% of y = 5
   

   ⇒ y ×	95	= 5
   	100

   
   

   Correct Option: B

   Let the total quantity of sugar be y kg.
   According to the question,
   (100 – 5)% of y = 5
   

   ⇒ y ×	95	= 5
   	100

   
   

   ⇒ y =		500	=	100	= 5	5	kg.
   		95		19		19

   
   

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520. 12 copies of a book were sold for Rs. 1800 thereby gaining cost price of 3 copies. The cost price of a copy of the book is :

1. 1. Rs. 120

   
   
   

   2. Rs. 150

   
   
   

   3. Rs. 1200

   
   
   

   4. Rs. 1500

   
   
   

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1. View Hint View Answer Discuss in Forum

   Let the C.P. of each book be Rs. y.
   According to the question ,
   S.P. of 12 copies = Rs. (12y + 3y) = Rs. 15y
   ∴ 15y = 1800
   

   Correct Option: A

   Let the C.P. of each book be Rs. y.
   According to the question ,
   S.P. of 12 copies = Rs. (12y + 3y) = Rs. 15y
   ∴ 15y = 1800
   

   ⇒ y =	1800	= Rs. 120
   	15

   
   

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