If you fail, never give up because FAIL means 'First Attempt In Learning'.— A. P. J. Abdul Kalam

Problem Solving — quick quiz

5 real SOF IMO questions on Problem Solving. Instant scoring and solutions, no signup — see where you stand in ~3 minutes.

Question 1 of 5

HARD

The average of 6 numbers is 42. If one number is excluded, the average becomes 38. What is the excluded number?