9. A grocer wants to mix a type of spice which costs £22 per kilogram with another

Question

type which costs £12 per kilogram, to obtain 20 kilograms of mixture which will
cost £15 per kilogram. What quantity of each spice must the grocer take?

Answer 1

let a = 22 / kg, and b = 12 / kg

a + b = 20 kg

22a + 12b = 15 * 20

12a + 12b = 240

10a = 60