I went into a self-service shop the other day and selected four items to buy. At the checkout I was told that the total cost was £7.11. Thinking this was too high I asked how the figure had been reached. The assistant said that she had simply multiplied the prices of the four individual items. I protested that the four prices should have been added, not multiplied. The assistant said that that was OK with her, but the result was still the same - exactly £7.11. What were the prices of the four items?
