Why are bananas so cheap to buy in the UK? In a big supermarket, a single banana costs about 15p, but presumably it has been shipped thousands of miles at some expense. Other individually sold fruit – even the stuff grown in the UK – seems to cost two or three times as much. Magdalena, by email

Post your answers (and new questions) below or send them to nq@theguardian.com. A selection will be published next Sunday.