481. By selling 14 watches of equal cost price at the rate of $ 450 each, there is a profit equal to the cost price of 4 watches. The cost price of a watch is

1. 1. $ 350

   
   
   

   2. $ 360

   
   
   

   3. $ 375

   
   
   

   4. $ 400

   
   
   

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1. View Hint View Answer Discuss in Forum

   Let the CP of each watch be y.
   ∴ CP of 14 watches = 14y
   and SP of 14 watches = $ 6300
   According to the question,
   6300 – 14y = 4y
   ⇒ 18y = 6300
   

   Correct Option: A

   Let the CP of each watch be y.
   ∴ CP of 14 watches = 14y
   and SP of 14 watches = $ 6300
   According to the question,
   6300 – 14y = 4y
   ⇒ 18y = 6300
   

   ⇒ y =	6300	= $ 350
   	18

   
   Hence , CP of each watch is $ 350 .

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482. A man buys some articles at $ P per dozen and sells them at $ (P / 8) per piece. His profit per cent is

1. 1. 30%

   
   
   

   2. 40%

   
   
   

   3. 50%

   
   
   

   4. 60%

   
   
   

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1. View Hint View Answer Discuss in Forum

   Given in question, CP of 12 articles = $ P
   

   ∴ CP of each article = $		P	and SP = $	P
   		12		8

   
   

   Correct Option: C

   Given in question, CP of 12 articles = $ P
   

   ∴ CP of each article = $		P	and SP = $	P
   		12		8

   
   

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483. A person bought 50 pens for $ 50 each. He sold 40 of them at a loss of 5%. He wants to gain 10% on the whole. Then his gain per cent on the remaining pens should be

1. 1. 15%

   
   
   

   2. 40%

   
   
   

   3. 50%

   
   
   

   4. 70%

   
   
   

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1. View Hint View Answer Discuss in Forum

   Here , C.P. of 1 pen = $ 50
   ∴ C.P. of 50 pens = 50 × 50 = $ 2500
   For profit of 10% ,
   

   S.P. =	2500 × 110	= $ 2750
   	100

   
   

   S.P. of 40 pens at a loss of 5% =	40 × 50 × 95	= $ 1900
   	100

   
   ∴ S.P. of remaining 10 pens = 2750 – 1900 = $ 850
   

   Correct Option: D

   Here , C.P. of 1 pen = $ 50
   ∴ C.P. of 50 pens = 50 × 50 = $ 2500
   For profit of 10% ,
   

   S.P. =	2500 × 110	= $ 2750
   	100

   
   

   S.P. of 40 pens at a loss of 5% =	40 × 50 × 95	= $ 1900
   	100

   
   ∴ S.P. of remaining 10 pens = 2750 – 1900 = $ 850
   Gain = S.P. of remaining 10 pens - C.P. of remaining 10 pens = 850 - 500 = $ 350
   

   ∴ Gain % =	350	× 100 = 70 %
   	500

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484. A vendor sells lemons at the rate of 5 for $ 14, gaining thereby 40%. For how much did he buy a dozen lemons?

1. 1. $ 20

   
   
   

   2. $ 21

   
   
   

   3. $ 24

   
   
   

   4. $ 28

   
   
   

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1. View Hint View Answer Discuss in Forum

   Given that , S.P. of 5 lemons = $ 14
   On gain 40% ,
   

   C.P. of 5 lemons =	100	× 14 = $ 10
   	140

   
   

   ∴ C.P. of 12 lemons =	10	× 21 = $ 24
   	5

   
   We can find required answer with the help of given formula :
   Here, a = 12, p = ? and b = 5, q = 14, Gain% = 40%
   

   Gain% =		aq - bp			× 100%
   		bp

   
   

   Correct Option: C

   Given that , S.P. of 5 lemons = $ 14
   On gain 40% ,
   

   C.P. of 5 lemons =	100	× 14 = $ 10
   	140

   
   

   ∴ C.P. of 12 lemons =	10	× 21 = $ 24
   	5

   
   We can find required answer with the help of given formula :
   Here, a = 12, p = ? and b = 5, q = 14, Gain% = 40%
   

   Gain% =		aq - bp			× 100%
   		bp

   
   

   40% =		12 × 14 - 5 × p			× 100%
   		5p

   
   ⇒ 2p = 168 – 5p
   ⇒ 7p = 168
   ⇒ p = 24

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485. By selling 12 oranges for $ 60, a man loses 25%. The number of oranges he has to sell for $ 100, so as to gain 25% is
     

1. 1. 10

   
   
   

   2. 11

   
   
   

   3. 12

   
   
   

   4. 15

   
   
   

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1. View Hint View Answer Discuss in Forum

   Given that , Selling Price of 12 oranges = $ 60 ,
   On loss 25% ,
   

   C.P. of 12 oranges = 60 ×	100	= $ 80
   	75

   
   For a gain of 25%,
   

   Correct Option: C

   Given that , Selling Price of 12 oranges = $ 60 ,
   On loss 25% ,
   

   C.P. of 12 oranges = 60 ×	100	= $ 80
   	75

   
   For a gain of 25%,
   

   S.P. of 12 oranges =	80 × 125	= $ 100
   	100

   
   Hence, 12 Orange has to sell, [You can also check through options]

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