Further example for Higher tier
Here are details found in a paint shop:
Calculate the price of buying 1.5 litres of Burnt Sunset and of buying 3.5 litres of Fiesta Lights.
Solution
Work out the price of 1.5 litres of Burnt Sunset
Burnt Sunset is made up of 5 parts red and 7 parts yellow = 12 parts.
We want 1.5 litres = 1,500 ml
1,500 ÷ 12 = 125 ml for every ‘part’ in the ratio.
So we want:
- 5 × 125 = 625 ml red
- 7 × 125 ml yellow = 875 ml
Which costs:
- 6.25 × £1.40 = £8.75 and
- 8.75 × £1.25 = £10.9375 = £10.94
So the total for Burnt Sunset paint is £8.75 + £10.94 = £19.69
Work out the price of 3.5 litres of Fiesta Lights
Fiesta Lights is made up of 2 parts yellow, 5 parts red and 7 parts blue = 14 parts.
We want 3.5 litres = 3,500 ml
3,500 ÷ 14 = 250 ml for every ‘part’ in the ratio.
So we want:
- 2 × 250 = 500 ml yellow
- 5 × 250 = 1,250 ml red
- 7 × 250 = 1,750 ml blue
Which costs:
- 5 × £1.25 = £6.25 and
- 12.5 × £1.40 = £17.50 and
- 17.5 × £1.50 = £26.25
So the total for Fiesta Lights paint is £6.25 + £17.50 + £26.25 = £50.00
