From a 1968, O-level Maths paper. One of two that gave you two hours to answer umpteen questions you wouldn't find on most A-level courses these days.
Cf: GCSE "Higher" Tier, June 2008.
And:Still haven't worked it out? I'll give you a clue: one is a Maths exam for 16 year-olds being trained for adulthood and a working life, the other is an infantile joke that 600,000 British "kids" preparing for a life of texting each uvva and the dole have just "passed".
We're finished. And socialism finished us.