A high school sponsored a badminton tournament. After each round, one-half of the players were eliminated. If there were 64 players at the start of the tournament, which equation models the number of players left after round 3? (1) y=64(1-.5)^3
(2) y=64(1+.5)^3
(3) y=64(1-.3)^.5
(4) y=64(1+.3)^.5

(1) y = 64(1 - .5)^3

Step-by-step explanation:

(1) y = 64(1 - .5)^3

If you are eliminated half, then you are removing 50% or .5 of the teams. The number of teams is getting smaller, so eliminate the choices with "+". The exponent refers to the number of rounds.

This is an easy one to check: 64, 32, 16, 8. There are 8 teams after three rounds.

y=64(1 - .5)^3

y= 64(.5)^3

y= 64(.125)

y= 8