Water freezes at 0°Celsius (32°Fahrenheit) and boils at 100°C (212°Fahrenheit). Is there a temperature at which Celsius and Fahrenheit readings are the same?
When I park my car in Mathstown, there are two car parks to choose from. Which car park should I use?
Change one equation in this pair of simultaneous equations very slightly and there is a big change in the solution. Why?
How many intersections do you expect from four straight lines ? Which three lines enclose a triangle with negative co-ordinates for every point ?
Which is bigger, n+10 or 2n+3? Can you find a good method of answering similar questions?