Higher November 2021 Paper 4 Q6
6 A shop sells the same milk in three different sized cartons.
The diagram shows the price of each carton.
(a) Which carton is the best value for money?
Show how you decide. [3]
Show how you decide. [3]
(b) A student only buys milk on a Saturday morning.
They use 120 ml of milk each day.
Any unused milk has to be thrown away at the end of the following Friday.
They use 120 ml of milk each day.
Any unused milk has to be thrown away at the end of the following Friday.
Show that it is cheaper for the student to buy the milk they need in 300 ml cartons than in 500 ml cartons. [3]
| Answer | Marks | Part marks and guidance | |
|---|---|---|---|
| 500 ml with three correct comparisons | 3 | Allow any correct comparison e.g.(converting all to 500 ml) B2 for three correct figures to compare or B1 for two correct figures OR M1 for one correct appropriate calculation e.g. 1.96 ÷ 4 or 31 × 5 ÷ 3 oe | See appendix for other values e.g. 49[p] is sufficient for B1 as it compares to 47[p] |
Appendix: Question 6(a)
Numbers should be given to sufficient accuracy to enable a decision to be made, usually 2 figures and can be truncated or rounded. These figures are in pence or ml and act as a guide. If they convert to, say 2 litres, they only need to work out two figures as one is given.
Converting all to 100 ml : 10.333…, 9.4, 9.8
Converting all to 500 ml : 51.666…, 47, 49
Converting all to 1 litre : 103.333…, 94, 98
Amount for 10p : 96.774…, 106.3829…, 102.0408…
| Answer | Marks | Part marks and guidance | |
|---|---|---|---|
| 7 × 120 soi by 840 | M1 | accept any correct argument | Condone omitting one day so 6 × 120 soi by 720 for M1 |
| 840 ÷ 300 soi by 2.8 or 3 and 3 × 31 = 93[p] | B1 | 3 × 31 = 93[p] is sufficient | |
| 840 ÷ 500 soi by 1.68 or 2 and 2 × 47 = 94[p] | B1 | If B0 then SC1 for 3 [of 300 ml] and 2 [of 500 ml] | 2 × 47 = 94[p] is sufficient |