Question

Can someone please explain how to do this problem?

A regional soccer tournament has 64 participating teams. In the first round, the number of games played decreases by a factor of one half. Find a rule for the number of games played in the regional soccer tournament.

I tried using the formula An=a1(r)^n-1 but I don't think that's right. I also tried using the formula a1(1-r^n/1-r). Am I doing something wrong or not using the right formula?

Answer 1

The second formula is correct

The games played are 32,16,8,4,2,1
a1=32, r = 1/2 and there are 6 rounds played.

32(1 - 1/2^6)/(1 - 1/2)
= 32(63/64)/(1/2)
= 63