Joe leaves his house at 3.50 am, with 17.60 in his pocket. He arrives at the all-night garage at 3.57 am, and buys the following;
8 Kit-Kats, at 40 pence each
2 tubes of Pringles, at 1.65 each
3 Pepperami Firesticks, at 70 pence each
2 Litre bottles of Ginger Ale, at 1.19 each
Now; before he left his house, how many joints did Joe smoke?