Green paint is made by mixing blue, yellow and white paints in the ratio 2: 7: 1. How much blue paint is needed to make 64 litres of green paint?

Here, sum of ratios = 2 + 7 + 1 = 10
∴ Total quantity of green paint = 64 litres

Quantity of blue paint = (2/10) × 64 = 12.8 litres

Therefore, the required blue paint = 12.8 litres.