Which of these is NOT a valid denomination of UK currency?

Okay, let's talk about UK currency. The British monetary system is based on the pound sterling, which is divided into 100 pence. You'll commonly find coins like the 1p, 5p, 10p, 20p, and 50p. We also have £1 and £2 coins. Now, while you might be familiar with other countries having a 25-cent coin, the UK doesn't have a 25p coin. It's a bit of a trick question because it sounds plausible, but it's simply not a denomination that exists in British currency. So, if you're ever paying for something in the UK, don't expect to find a 25p coin in your change! It's a good way to remember the actual denominations and avoid confusion.