# Question 3

3.1 As availability of water is becoming a major problem in South Africa, more
people are intending to save water. Therefore some of them are
investigating how they are billed and if the billing is correctly calculated.

Mrs. Treace is one of those people and stays in Cape Town. She studied the
water tariffs for 2013–2014 carefully.

Below is a table showing the water tariffs for Cape Town during
2013–2014. Study the table carefully before answering the questions.

3.1.1 Calculate the missing values for A and B respectively. (4)

3.1.2 If Mrs. Treace uses on average 19,5 kl of water per month, will she
be paying for the full 19,5 kl? Give a reason for your answer. (2)

3.1.3 Hence, calculate how much Mrs. Treace will pay for using 19,5 kl of
water including VAT. (4)

Below are diagrams of a vertical, round water tank and a rectangular water
tank. Study these diagrams and the information given and then answer the
questions that follow.

3.2.1 Show with the necessary calculations that the volume of the vertical
round water tank numbered 1 is not exactly 1000 liters as indicated
in the table.

Use the formula:
Volume of vertical round water tank = 3,142 x radius2 x height of the water tank.
Please Note: 1 m3 = 1000 l (6)

3.2.2 With reference to your answer in QUESTION 3.2.1, why do you
think that there is a difference in the volume between what you have
calculated and the given volume? Also explain how this given
information can be misleading to consumers. (3)

3.2.3 Briefly explain why the diagrams indicate a recommended filled
height. (2)

3.2.4 In her backyard, Mrs. Treace has only one open area next to her
house to install the water tank. The width of the area is 1,15 m.
Which of the water tanks must she buy that will satisfy the
requirement? (2)

3.3 Mrs. Treace will be using the water in her water tank for various purposes. If
Mrs. Treace wants to illustrate her usage graphically, which graphical
representations can Mrs. Treace use to illustrate how she is using the
water? (2)

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