Higher November 2018 Paper 2 Q10
10 Robert makes 50 litres of green paint by mixing litres of yellow paint and litres of blue paint in the ratio 2 : 3
Yellow paint is sold in 5 litre tins.
Each tin of yellow paint costs £26
Blue paint is sold in 10 litre tins.
Each tin of blue paint costs £48
Robert sells all the green paint he makes in 10 litre tins.
He sells each tin of green paint for £66.96
Work out Robert’s percentage profit on each tin of green paint he sells. (5)
| Answer | Mark | Mark scheme |
|---|---|---|
| 35 | P1 | use of ratio 2:3 and tin quantities to find overall ratio of litres eg 4:3 or 4 tins : 3 tins or 20 litres (Y) & 30 litres (B) |
| P1 | calculates total cost of making paint eg \(4 \times 26 + 3 \times 48\) (50 litres) or \(104 + 144\ (= 248)\) | |
| A1 | calculates comparable cost eg 10 litres (1 tin) green paint made as 49.6 or differences (profit) for 1 tin as 17.36 or 5 tins as 86.8 or total comparable costs for 50 litres as 334.8 and 248, for 25 litres as 167.4 and 124 or 1 litres as 33.48 and 24.8 | |
| P1 | for percentage calculation eg \(\dfrac{1736}{4960} \times 100\), \(\dfrac{\text{``}334.8\text{''} - \text{``}248\text{''}}{\text{``}248\text{''}} \times 100\) | |
| A1 | cao |
Additional guidance
Could be multiples 4 & 3 (for an amount which is a multiple of 50 litres).
“248” is the total cost for making 50 litres
\(\text{``}248\text{''} \div 5 = 49.6\) for 10 litre (1 tin) green paint made
Profit on 10 litres is \(66.96 - 49.60 = 17.36\)
Profit on 50 litres is \(334.8 - 248 = 86.8\) (corrected from the printed mark scheme: 304.8)
334.8 comes from \(5 \times 66.96\) and is the selling price for 50 litres green paint