Most adults would like to think school has left them equipped for most things that life throws at them. But a particularly tricky IQ test has left internet users stumped, pushing their mathematical and linguistic skills to the limit. Jumping right in at the deep end with a complicated numerical question, the Playbuzz quiz is certainly not for the fainthearted. Try your hand at the quiz to see how you score, and scroll down to the bottom for answers (no cheating!)