More or Less: Behind the Stats - A&E, and the chances of having twins

A&E waiting times have been making the headlines - Tim Harford takes a look at some of the numbers and puts them into context. Today presenter Evan Davis explains his frustration with finding official statistics online. We explore if men really do think about sex every seven seconds. Plus, what are the chances of having twins?

More or Less: Behind the Stats - The maths of spies and terrorists

In the wake of the Boston Marathon bombing and the killing of a British soldier on the streets of Woolwich in London, it emerged that the suspects were known to the security services. But how feasible is it for the authorities to keep track of everyone on their watch list? Tim Harford crunches the numbers, with the help of the former head of the UK intelligence service MI5, Dame Stella Rimington.