WS MoreOrLess: Nuns on the rise

It was recently reported that the number of women training to become Catholic nuns in Great Britain has reached a 25-year high. What's the long-term trend – are more women becoming nuns? Tim Harford looks at figures from the UK and across the world. Plus, Matt Parker the stand-up mathematician is invited back to the programme to respond to a listener's query about his theory on the best way to find a life partner.