Introduction - If you have any usage issues, please Google them yourself
Joseph game of life and death
30 passengers with a boat ride, due to stormy, 15 people must be dropped in order to ensure safety. Now 30 people stand in a circle. A number of people the number to the first nine people when it threw. Then start counting the next person, the number to the 9th person is to be thrown. And so on, until the rest of the 15 people so far. Who will find the rest.