方程式(英文) - Ans.fyi 參考答案

方程式(英文)

霜影

2009-11-11 6:02 am

1.An adult ticket for a drama show costs $75 while a student ticket costs $30.If the total revenue of the show is $72,000 and 1200 tickets are sold,how many student tickets have been sold?

2.John's savings is $300 more then his sister's.After giving $450 of his savings to his sister,John's savings becomes 2 over 5 of his sister's.How much savings do they have altogether?

3.
City A is 100km to the west of city B.David rides a bicycle 15km/h from city A to the west.At the same time,Alice drives a car y km/h from city B to the west.

3a.Express,in terms of y,the distance between David and Alice after 2 hours.

回答 (1)

用戶9112

2009-11-11 6:23 am

✔ 最佳答案

(1) Let the number of student tickets sold be x
Then the number of adult tickets sold = 1200 - x
Total revenue = 30x + 75(1200 - x) = 72000
30x + 90000 - 75x = 72000
18000 = 45x
x = 400
400 student tickets have been sold.
(2) Let John's saving be $x
The the saving of his sister = $(x - 300)
They have in total x + x - 300 = $(2x - 300)
x - 450 = (2/5)(x - 300 + 450)
5(x - 450) = 2(x + 150)
5x - 2250 = 2x + 300
3x = 2550
x = 850
They have in total = $(1700 - 300) = $1400
(3) After two hours, David would have travelled 15 * 2 = 30km
Alice would have travelled 2y km
The original distance between David and Alice was = 100km
After two hours their distance will be | 100 + 30 - 2y | = | 130 - 2y | km

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