The bizarre story of the Scottish programmer found dead in his car half a mile away from a box of deadly snakes reads like one of those conundrums popular with secondary school science teachers (in my case Mr Mainwaring, Physics). Here are a few ones I remember:

• A man was found dead in the bottom of a phone box. The only things with him in the phone box (apart from the phone) were a fishing rod and some broken glass. How did he die?

• Every day a man leaves his apartment on the 46th floor and rides the lift down to the first floor to go to work. Every evening at about 6 pm he gets in the lift, takes the lift up to the 38th floor, gets out and walks up the stairs the for the remaing eight floors until he reaches the 46th floor. Why?

• Two people were born within minutes of each other by the same mother, but they weren’t twins. How is this possible?