A trader sells pistachios at $10/kg, almonds at $12/kg and peanuts at $8/kg. It prepares a mixture for 100 packages of 1 kg which he sells for $9 each. The mixture must earn him the same amount as if he sold pistachios, almonds and peanuts separately.

a) Give the composition of a package.

b) Give the composition of a package that would contain twice as much peanuts than pistachios.

c) Can a package contain a quantity of peanuts four times superior to pistachios and almonds combined?