F3-F4 MATHS!!

2007-08-28 5:44 am

1.A hawker bought 120 oranges at $1 each.However 5% of them were damaged and had to be thrown away.Another 20% of them were in poor quality and had to be sold at half of the marked price.He then sold the rest at a profit of 40%.
(a)find the total cost
(b)find the selling price of each normal orange
(c)find the total revenue by selling the oranges
(d)find the overall profit percentage

please write steps and answers
thank you very much

更新1:

2.Ship A is due west of a lighthouse and Ship B is due east of the lighthouse.From the top pf the lighthouse, a man finds the angle of depression of the two ships to be 25(。) and 35(。) respectively.If the height of the lighthouse is 100m,find the distance between the two ships.

回答 (1)

2007-08-28 6:07 am

✔ 最佳答案

total cost : ($1)*120*5%+($0.5)*120*20%=$18
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selling price : ($1)*(1+40%)=$1.4
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total revenue by selling the oranges : 120*(1-25%)*[($1)*(1+40%)]=90*($1.4)=$126
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the overall profit percentage : (126-120/120)*100%=5%
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Ship A is due west of a lighthouse and Ship B is due east of the lighthouse
so Ship A and Ship B are in the same line.
a man finds the angle of depression of the two ships to be 25(。)
and 35(。) respectively
and the height of the lighthouse is 100m
so the distance of Ship A from the lighthouse is 100m*tg25(。)
the distance of Ship B from the lighthouse is 100m*tg35(。)
so the distance between the two ships is 100*(tg25(。)*tg35(。))m

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