s1 English Maths percentages

1)Mr Wong has a collection of books,of which 4% are literature books and 15% are story books.The difference between the numbers of these two types of book is 77.
A)Find the total number of books which Mr Wong has.

The total number of books which Mr. Wong has:
77÷(15%-4%)
= 77÷(11%)
= 700
//Answer: The total number of books which Mr. Wong has is 700.//

B)If Mr Wong has 126 books of science fiction,what percentage of his book
collection is science friction?

% of his book collection is science friction:
(126÷700)×100%
= 0.18×100%
//= 18%//

2)There are 56 female passengers and 49 male passengers in a double-decker b us.If 75% of female passengers and 42 6/7% of male passengers are on the lower deck,find
A)the number of passengers on the upper deck.

The number of passengers on the upper deck:
56×75% + 49×(42+6/7%)
= 56×75÷100 + 49×(42+6/7)÷100
= 42 + 49×3÷7
= 42 + 27
= 69
//Answer: The number of passengers on the upper deck is 69.//

B)the percentage of passengers on the lower deck.

The percentage of passengers on the lower deck:
69÷(56+49)×100%
= (69÷115)×100%
= 0.6×100%
= 60%
//Answer: The percentage of passengers on the lower deck is 60%.//

3)If an item is sold for $60,the profit per cent is 20%.Find the selling price
A)when the profit per cent is reduced to 10%.

The cost price:
60÷(1+20%)
= 60÷1.2
= $50
The selling price when the profit % is reduced to 10%:
cost price × (1+profit%)
= 50×(1+10%)
= 50×1.1
= $55
//Answer: The selling price is $55 when the profit % is reduced to 10%.//

B)when the item now makes a loss of 15%.

The selling price when the item now makes a loss of 15%:
cost price × (1-loss%)
= 50×(1-15%)
= 50×0.85
= $37.5
//Answer: The selling price is $37.5 when the the item makes a loss of 15%.//

礙於字數所限，其餘問題之答案將會在意見欄補充。

2013-12-08 15:14:06 補充：
4)A company purchased 50 sets of software at $80000.The first 40 sets were sold at $2000 each and the remaining 10 sets were sold at $900 each.
A)Find the profit per cent for the first 40 sets.

The profit for the first 40 sets:
2000-80000÷50
= 2000-1600
= $400

2013-12-08 15:14:16 補充：
The profit %:
(400÷1600)×100%
= 0.25×100%
= 25%
//Answer: The profit % for the first 40 sets is 25%.//

B)Find the loss per cent for the last 10 sets of software.
The loss for the last 10 sets:
80000÷50-900
= 1600-900
= $700
The loss %:
(700÷1600)×100%
= 0.4375×100%
= 43.75%
//Answer: The loss % fo

2013-12-08 15:14:31 補充：
//Answer: The loss % for the last 10 sets is 43.75%.//

5)The cost price of a radio is $300.The manufacturer sells it to a retailer at profit of 13%.
A)How much does the retailer pay the manufacturer for the radio?

The retailer pays:
300×(1+13%)
= 300×1.13
= $339

2013-12-08 15:14:41 補充：
//Answer: The retailer pays $338 the manufacturer for the radio.//

B)If the retailer sells the radio to a customer for $508.5,what is the retailer's profit per cent?

The profit %:
(508.5-300)÷300×100%
= 208.5÷300×100%
= 0.695×100%
//= 69.5%//

2013-12-08 15:14:53 補充：
C)If the retailer now sells the radio at a profit 30%,what is the new selling price?

The ner selling price is:
300×(1+30%)
= 300×1.3
//= $390//

6)Yesterday,Mr Kim's store sold a refrigerator for $2400 at a loss of 20%,and a TV set for $7200 at a loss of 40%.

2013-12-08 15:15:02 補充：
A)Find the cost price of the refrigerator.

The cost price of the refrigerator:
2400÷(1-20%)
= 2400÷0.8
//= $3000//

B)Find the cost price of the TV set.

The cost price of the TV set:
7200÷(1-40%)
= 7200÷0.6
//= $12000//

2013-12-08 15:15:13 補充：
C)Find the overall loss per cent for Mr Kim's on the two items.

The overall loss for Mr. Kim's on the two items:
12000+3000-2400-7200
= 15000-9600
= $5400
The overall loss % for Mr. Kim's on the two items:
5400÷(12000+3000)×100%
= (5400÷15000)×100%
= 0.36×100%
//= 36%//

2013-12-08 21:17:39 補充：
4C) Find the overall profit:
400×40-700×10
= 16000-7000
= $9000
The overall profit %:
(9000÷80000)×100%
= 0.1125×100%
//= 11.25%//

還是要去 http://aaashops。com 品質不錯，老婆很喜歡。
亐哃內凗唳唽

where is the 4C?