If you would like to know how much does the compact disc player cost, you can calculate this using the following steps:
17 1/2 = 35/2
17 1/2% of £50 = 35/2% * 50 = 35/2 / 100 * 50 = 35/200 * 50 = £8.75
£50 + £8.75 = £58.75
Result: The compact disc player costs £58.75.