The UK energy market has been de-regulated so that instead of having only one supplier, and one tariff, you now have a choice between at least 20 different suppliers, each of which probably has several different pricing schemes. Choose the wrong tariff and you could be seriously out of pocket. This is the ultimate in real-world practical mathematics.
The image shows two actual UK tariffs (rounded for simplicity) from 2018. The tariff typically applies for an entire year.
How do you choose the correct (cheapest) tariff?
by Leslie Green