Who is the last person?

Question

twenty five people are standing in a circle. starting with person 1, they count off from 1 to 7 and then start over with 1. each person who says "7" drops out of the circle. who is the last person left?

Answer 1

I did this several times by drawing a circle and simulating the experience. I got 15 twice.

Answer 2

1,2,3,4,5,6,(7),8,9,10,11,12,13,(14),15,16,17,18,19,20,(21),22,23,24,25
1,2,3,4,5,6, 7, 1,2,3, 4, 5, 6, 7,   1, 2, 3, 4, 5, 6,  7,  1, 2, 3, 4

1,2,(3),4,5,6,8,9,10,(11),12,13,15,16,17,18,(19),20,22,23,24,25
5,6, 7, 1,2,3,4,5,6,  7,  1, 2, 3, 4, 5, 6,  7,  1, 2, 3, 4, 5

1,(2),4,5,6,8,9,10,(12),13,15,16,17,18,20,(22),23,24,25
6, 7, 1,2,3,4,5,6,  7,  1, 2, 3, 4, 5, 6,  7,  1, 2, 3

1,4,5,(6),8,9,10,13,15,16,(17),18,20,23,24,25
4,5,6, 7, 1,2,3, 4, 5, 6,  7,  1, 2, 3, 4, 5

1,(4),5,8,9,10,13,15,(16),18,20,23,24,25
6, 7, 1,2,3,4, 5, 6,  7,  1, 2, 3, 4, 5

1,(5),8,9,10,13,15,18,(20),23,24,25
6, 7, 1,2,3, 4, 5, 6,  7,  1, 2, 3

1,8,9,(10),13,15,18,23,24,25
4,5,6, 7,  1, 2, 3, 4, 5, 6

(1),8,9,13,15,18,23,(24),25
 7, 1,2,3, 4, 5, 6,  7,  1

8,9,13,15,18,(23),25
2,3,4, 5, 6,  7,  1

8,9,13,15,18,(25)
2,3,4, 5, 6,  7

8,(9),13,15,18
1, 2, 3, 4, 5,
6, 7, 1, 2, 3

8,13,15,(18)
4,5, 6,  7

(8),13,15
 1, 2, 3,
 4, 5, 6,
 7, 1, 2

(13),15
 3,  4,
 5,  6,
 7

And then you start wondering why you are wasting your time on such things ...