Question 9 — IGCSE 0580 Oct/Nov 2023 Paper 31
Cambridge IGCSE Mathematics 0580, Core tier, calculator. Topic: Numbers · Fractions, decimals and percentages. Worth 11 marks.
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Question text
9 (a) Pure gold costs $42 per gram.
The fraction of pure gold in an object is measured in carats.
1
One carat means of the mass of an object is pure gold.
24
Henry buys a 9-carat gold bracelet weighing 16 g.
The price of the bracelet is $204.
Is the price of the bracelet more or less than the cost of the pure gold in it?
You must show your working.
[4]
(b) A clock made of metals has a mass of 1080 g.
The mass of each metal in the clock is in the ratio
copper : zinc : other metals = 21 : 14 : 1.
Calculate the mass of copper in this clock.
.............................................. g [2]
© UCLES 2023 0580/31/O/N/23
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(c) There are 110 people in a group.
G = { people who own gold jewellery }
S = { people who own silver jewellery }
18 people own both gold jewellery and silver jewellery.
46 people own gold jewellery.
11 people own no gold jewellery and no silver jewellery.
(cid:31)
G S
(i) Complete the Venn diagram. [2]
(ii) Write down n(G+S).
................................................. [1]
(iii) One of the 110 people is chosen at random.
Write down the probability that this person owns gold jewellery but not silver jewellery.
................................................. [1]
(d)
(cid:31)
E F
Use set notation to describe the shaded region.
................................................. [1]
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