F.1英文數學題

[Use the steps and answer.(Don't give me answer only please.)

1) Two pipes A and B are joined to a water tank. To completely fill the water tank with water, pipe A alone takes 9 hours and pipe B alone takes 12 hours. If the capacity of the water tank is x m^3,

(a) Express the respective amounts of water filled by pipe A and pipe B each hour in terms of x.

(b) If pipe A and pipe B are used simultaneously to fill the water tank with water, there is 70 m^3 of water in the tank
after two hours. Find the capacity of the water tank.

2) Joseph participates in a competition. It is known that each participant has to answer x questions, where 30 marks
will be obtained for each correct answer, 20 marks will be deducted for each wrong answer and 0 mark for no answer. Joseph answers 3/8 of the questions correctly and gives up 8 questions.

(a) Express the number of questions Joseph answers wrongly in terms of x.

(b) If Joseph obtains 130 marks, find the value of x.

(c) Kenneth also participates in the competition. He answers 1/3 of the questions correctly and gives up 5/12 of the questions. Who obtains a
higher score, Joseph or Kenneth?

3) The marked price of a carton of Brand A milk is $18 at Lowly-priced Store and it is sold at a discount of 15%, while it is sold at $30 for two at Quality Store.

(a) Find the selling price of a carton of Brand A milk at Lowly-priced Store.

(b) Find the average selling price of a carton of Brand A milk at Quality Store.

(c) If two cartons of Brand A milk are to be bought, which store offers a lower selling price?