In the given figure, you can see that there are four circles numbered from 1 to 4. In the fourth circle, a digit is missing. Can you find out a relation and tell which number will suffice the pattern?
In 2011, people playing Foldit, an online puzzle game about protein folding, resolved the structure of an enzyme that causes an Aids-like disease in monkeys. Researchers had been working on the problem for 13 years. The gamers solved it in three weeks.