4 is probably the answer. Hope this helps. :)
Answer:
35 m/s
Step-by-step explanation:
Let gravitational acceleration g = 9.8m/s2. We can calculate the amount of time for the ball to fall vertically a distance of 1.6 m



This is also the time it takes for the ball to fly horizontally, assume constant horizontal speed, we can calculate the speed it takes to travel across 20m in 0.571s
v = 20 / 0.571 = 35 m/s
Answer:
7 rings = $2.52
then 1 ring will cost = 1/7×2.52
= 0.36
Therefore 1 ring will cost $0.36.