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GCSE · Ratio and Proportion

3.12D Best Buy Questions: Fluency and Exam Drill

EDEXCEL Edexcel 1MA1 · Calculator allowed · about 50 minutes

Total Marks

Name: _______________________________ Date: ____ / ____ / ______

Answer ALL questions. Show all your working.

Which is the better buy: 3 apples for 90p or 5 apples for £1.40? Work out the cheaper price per apple.

(Total for Question 1 is 1 mark)

Which is cheaper per litre: a 750 ml bottle for £1.20 or a 1.5 litre bottle for £2.50? Give the cheaper option and the price per litre.

(Total for Question 2 is 1 mark)

A 600 g bag of cereal costs £1.50. Work out the cost per 100 g.

(Total for Question 3 is 1 mark)

A chocolate bar is sold singly for 95p or as 4 bars for £3.20. Which is the better buy by unit price? Show your working.

(Total for Question 4 is 2 marks)

Which is better value per kg: a 2 kg bag of flour for £2.40 or a 500 g pack for 72p? Work out the cost per kg for both.

(Total for Question 5 is 2 marks)

A 1.2 kg bag of sugar costs £3.60. Work out the cost of 300 g of sugar.

(Total for Question 6 is 2 marks)

Compare three jars of jam and state which is best value per 100 g.
Small: 340 g for £1.65. Medium: 500 g for £2.40. Large: 1 kg for £4.25. Work out the price per 100 g for each and give the best value.

(Total for Question 7 is 3 marks)

A store sells pens at £3.20 each. Offer A is "buy one get one half price". Offer B is "3 for £5". Which offer gives the lowest price per pen? Show working.

(Total for Question 8 is 2 marks)

Show that the cheapest way to buy at least 2.5 litres of paint is to buy one 2 litre tin and one 750 ml pot.
750 ml pot costs £4.50. 2 litre tin costs £11.00. You must show costs for feasible combinations that reach at least 2.5 litres.

(Total for Question 9 is 3 marks)

A 750 g packet of couscous costs £2.10. Work out the cost of 1.5 kg of couscous.

(Total for Question 10 is 2 marks)

A pack of 6 toilet rolls costs £2.40. A pack of 12 costs £4.56. Which pack is better value per roll? Show your working.

(Total for Question 11 is 2 marks)

A chocolate costs £1.20 each. You can buy a pack of 5 for £5.00 or take a "3 for 2" offer in the shop. Which way is cheapest if you need 9 bars? Show working.

(Total for Question 12 is 3 marks)

A 2.25 kg bag of rice costs £4.95. Work out the cost per 100 g. Give your answer in pence.

(Total for Question 13 is 2 marks)

You need to fill a 40 litre petrol tank. Station A sells petrol at £1.349 per litre. Station B sells petrol at £1.329 per litre. How much would you save by filling at Station B instead of Station A? Give your answer to the nearest penny.

(Total for Question 14 is 2 marks)

An item normally costs £9.60 each.
Offer A: 3 for £25.00.
Offer B: Buy 2 get the 3rd half price.
Which offer gives the lower price per item, and by how much per item? Show working and give the saving per item in pence, to the nearest whole penny.

(Total for Question 15 is 4 marks)

Shampoo is sold in a 250 ml bottle for £3.60 and a 500 ml bottle for £6.40. Which bottle is better value per 100 ml? Show working.

(Total for Question 16 is 2 marks)

Compare three coffee options and state the cheapest per 100 g and how much cheaper per 100 g it is than the most expensive option.
A: 200 g jar £2.40. B: 500 g jar £5.70. C: 1 kg bag £10.80.
Work out per 100 g prices and the difference between best and worst.

(Total for Question 17 is 3 marks)

A shop sells small packets of biscuits as 5 for £6.75. Work out the cost of 8 packets.

(Total for Question 18 is 2 marks)

Mark scheme · 3.12D Best Buy Questions: Fluency and Exam Drill

Question 1

B1 Identify 5 for £1.40 is better value, 140p/5 = 28p each cao
Answer: 5 for £1.40 (28p each). 3 for 90p is 30p each, 5 for £1.40 is 28p each (better). 28p cao

Question 2

B1 750 ml bottle cheaper, 120p/0.75 = 160p per litre cao
Answer: 750 ml bottle, 160p per litre (cheaper than 166.67p per litre for 1.5 L).

Question 3

B1 25p per 100 g cao
Answer: 25p per 100 g (150p/600g = 0.25p per g, so 25p per 100 g).

Question 4

M1 Calculate unit prices: 95p for single, 320p/4 = 80p each
A1 State 4 for £3.20 is better value, 80p each cao
Answer: 4 for £3.20 is better value; 80p each rather than 95p each.

Question 5

M1 Calculate 2 kg bag: 240p/2 = 120p per kg; 500 g pack: 72p/0.5 = 144p per kg
A1 2 kg bag is better value, 120p per kg cao
Answer: 2 kg bag is better value: 120p per kg vs 144p per kg for the 500 g pack.

Question 6

M1 Scale: 300/1200 of £3.60 or 360p * 300/1200
A1 90p cao
Answer: 90p (360p * 300/1200 = 90p).

Question 7

M1 Calculate two unit prices, e.g. small 165p/340*100 = 48.53p, medium 240p/500*100 = 48p
M1 Calculate large: 425p/1000*100 = 42.5p
A1 Large jar is best value, 42.5p per 100 g cao
Answer: Small approx 48.53p per 100 g, Medium = 48p per 100 g, Large = 42.5p per 100 g. Best value = Large, 42.5p per 100 g.

Question 8

M1 Compute effective price: BOGOHalf two pens cost 3.20 + 1.60 = 4.80 so 2.40 each; 3 for £5 gives £1.666... each
A1 3 for £5 is cheaper, about £1.67 each cao
Answer: 3 for £5 is cheaper: effective price approx £1.67 per pen (BOGOHalf is £2.40 each).

Question 9

dM1 Calculate cost of 4 x 750 ml = 4 * £4.50 = £18.00 cso
dM1 Calculate cost of 1 x 2 L + 1 x 750 ml = £11.00 + £4.50 = £15.50 cso
A1 Conclude cheapest is 2 L + 750 ml = £15.50 cao
Answer: 1 x 2 L + 1 x 750 ml costs £15.50 and gives 2.75 L. Alternative 4 x 750 ml costs £18.00 (3.0 L). Therefore the cheapest way to get at least 2.5 L is 2 L + 750 ml costing £15.50.

Question 10

M1 Recognise 1.5 kg is 2 times 750 g and multiply: 2.10 * 2
A1 £4.20 cao
Answer: £4.20 (2 × £2.10).

Question 11

M1 Calculate unit prices: 240p/6 = 40p; 456p/12 = 38p
A1 12 pack is better value, 38p per roll cao
Answer: 12 pack is better value: 38p per roll (6 pack is 40p per roll).

Question 12

M1 Compute cost as singles: 9 * £1.20 = £10.80 or as two 5-packs = £10.00
M1 Compute cost with 3 for 2: for 9 bars pay for 6 -> 6 * £1.20 = £7.20
A1 3 for 2 is cheapest, £7.20 cao
Answer: 3 for 2 is cheapest: cost = £7.20 (pay for 6 bars). Singles cost £10.80, two 5-packs cost £10.00.

Question 13

M1 Calculate 495p / 2250 g * 100 to find per 100 g
A1 22p per 100 g cao
Answer: 22p per 100 g (495p / 2250 * 100 = 22p).

Question 14

M1 Calculate difference per litre: 1.349 - 1.329 = 0.020
A1 Saving = 0.020 * 40 = £0.80 cao
Answer: £0.80 saved (2.0 pence per litre × 40 litres = £0.80).

Question 15

M1 Calculate Offer A unit price: £25/3 = £8.333... per item
M1 Calculate Offer B unit price: for 3 items cost = 9.60 + 9.60 + 4.80 = £24 -> £8.00 per item
A1 State Offer B is cheaper cao
A1 State saving per item approx £0.333... -> 33p per item (awrt 33p) cao
Answer: Offer B is cheaper. Offer A = £8.333... per item, Offer B = £8.00 per item. Saving approx £0.333... = 33p per item (to nearest penny).

Question 16

M1 Calculate per 100 ml: 250 ml bottle = 360p/250*100 = 144p; 500 ml bottle = 640p/500*100 = 128p
A1 500 ml bottle is better value, 128p per 100 ml cao
Answer: 500 ml bottle is better value: 128p per 100 ml (250 ml bottle is 144p per 100 ml).

Question 17

M1 Calculate unit prices: A = 240p/200*100 = 120p; B = 570p/500*100 = 114p; C = 1080p/1000*100 = 108p
M1 Identify cheapest = C at 108p per 100 g
A1 State difference worst - best = 120p - 108p = 12p cao
Answer: Per 100 g: A = 120p, B = 114p, C = 108p. Cheapest is C (108p per 100 g). It is 12p per 100 g cheaper than the worst (A).

Question 18

M1 Find unit price: £6.75/5 = £1.35 and multiply by 8
A1 £10.80 cao
Answer: £10.80 (unit price £1.35 × 8 = £10.80).

Best Buy Questions: Fluency and Exam Drill - Worksheets, Questions and Revision