Ratio & Basic Proportion: WJEC GCSE Numeracy Intermediate November 2018 Unit 2 Q8

Numeracy Intermediate November 2018 Unit 2 Q8

WJECIntermediateCurrent spec8 marksRatio & Basic Proportion Rounding

8. Amrit and Gareth are planning to go to Switzerland.
The table below shows the rates for exchanging British pounds (£) and Swiss francs (CHF) at a money exchange shop.

Buy Swiss francs (CHF)	£1 buys 1.24 CHF
Sell Swiss francs (CHF)	1.28 CHF buys £1

The exchange shop:

has all possible British notes and coins,
sells and buys CHF notes only (no coins are available or accepted),
has 10 CHF, 20 CHF, 50 CHF, 100 CHF, 200 CHF and 1000 CHF notes.

(a) Amrit has £480 to buy Swiss francs.
Calculate

the maximum number of Swiss francs that Amrit can buy, and
how much, to the nearest penny, this will cost him.

You must show all your working. [5]

(b) Gareth paid £250 to buy 310 CHF.
Unfortunately, he is now unable to go to Switzerland.
How much will Gareth lose in selling 310 CHF back to buy pounds? [3]

Mark scheme (a)

Scheme	Marks	Comments
(Change to CHF) 480 × 1.24	M1	(= 595.2 CHF)
(No coins, so can buy only) 590 (CHF)	A2	A1 for an answer of 595(.2 CHF)
(Cost to Amrit for 590 CHF is ) 590 ÷ 1.24 OR 480 - (595.2 – 590) ÷ 1.24	M1	FT ‘their whole number multiple of 10 CHF’ ÷ 1.24 or 595 ÷ 1.24
(£) 475.81	A1	Depends only on previous M1 awarded Do not FT from 595 ÷ 1.24 Must be to the nearest penny, do not accept (£)475.8(0) If no marks, due to consistent use of 1.28 then SC1 for sight of 610 CHF AND SC1 for (£)476.56

Mark scheme (b)

Scheme	Marks	Comments
310 ÷ 1.28	M1
(£) 242.19 or (£) 242.18(75)	A1	Do not accept (£) 242.2(0)
(Loss £250 - (£) 242.19 =) (£) 7.81(25)	A1	FT 250 – ‘their (£) 242.19’ (use of £242.18 leads to £7.82) Mark final answer, i.e. not accepting rounding final answer to (£)7.80

Alternative

8(b) Alternative method:

Scheme	Marks	Comments
250 × (1.28 – 1.24) (= 10 CHF)	M1
÷ 1.28	m1
(£) 7.81(25)	A1	Mark final answer, i.e. not accepting rounding final answer to (£)7.80