Quiz..........
펌 : http://firejune.com/page/3 This is a mathematical challenge, and it's been said that: If you're an engineer, you should be able to solve it in (under) three minutes, If you're an architect, in three hours; If you're a doctor, in six hours; If you're an accountant, in three months and If you're a lawyer, probably never. What is the missing number in this logical series? 1, 2, 6, 42, 1806, ___..