Twenty people seated in a circle counted to seven, beginning with the number one. The seventh person dropped out and those remaining counted to seven again. If every seventh person dropped out, what was the number of the last person remaining in the circle? Use the number circle to simulate the problem.

Question

anonymous · Answer

attachment

kinggeorge · Answer

I think you can circle the numbers on your own, but we can help you get started. As seen in the diagram, 7 drops out first so you circle it. Next, you count 7 more starting at 8. So the next number you would circle is 14. Now count to 7 again starting at 15. This means we get to 1. So we circle 1, and continue.

kinggeorge · Answer

Now we start at 2, and count 7 more. But wait! 7 is already circled, so we just skip it. That means that 9 is the next number we circle. Can you tell me what the next number to be circled is?

anonymous · Answer

is it 9?

kinggeorge · Answer

After 9, what's the next number circled?

anonymous · Answer

17?

kinggeorge · Answer

Correct!. Now just continue that pattern until you don't have any numbers uncircled.

anonymous · Answer

ok cool thanks

kinggeorge · Answer

Let me know what your final answer is and I can check it for you.

kinggeorge · Answer

I've actually got to go now, but I should be back in an hour so to check the solution if you want.