Robert makes 50 litres of green paint by mixing litres of yellow paint and litres of blue paint in the ratio 2:3 - Edexcel - GCSE Maths - Question 10 - 2018 - Paper 2

Next, we calculate the total cost of the yellow and blue paint.

The yellow paint is sold in 5 litre tins:

• Number of tins of yellow paint = $\frac{20}{5} = 4$.
• Cost per tin of yellow paint = £26.
• Total cost for yellow paint = $4 \times 26 = 104$.

The blue paint is sold in 10 litre tins:

• Number of tins of blue paint = $\frac{30}{10} = 3$.
• Cost per tin of blue paint = £48.
• Total cost for blue paint = $3 \times 48 = 144$.

Thus, the total cost for making 50 litres of green paint is:

Total cost = £104 + £144 = £248.

Robert sells green paint in 10 litre tins:

• Total number of tins of green paint = $\frac{50}{10} = 5$.
• Selling price per tin of green paint = £66.96.
• Total selling price for 5 tins = $5 \times 66.96 = 334.80$.

Now, profit can be calculated as:

Profit = Total selling price - Total cost = £334.80 - £248 = £86.80.

Profit per tin = $\frac{86.80}{5} = 17.36$.

To calculate the percentage profit based on the cost price, we use the formula:

$\text{Percentage Profit} = \left( \frac{\text{Profit}}{\text{Cost Price}} \right) \times 100$.

Here, Cost Price per tin = $\frac{248}{5} = 49.60$.

Thus, plugging in the values gives:

$\text{Percentage Profit} = \left( \frac{17.36}{49.60} \right) \times 100 \approx 35\%$.