Quick equation forming help

[mikeras]

Here is a relevant excerpt:

In this new carnival game, square grids are drawn on the ground. The distance between lines is d mm. Players would throw toonie coins 28mm of diameter into the grid (of very large size). If the coin touches or crosses any line, they lose the coin; if it does not touch any line, they get a reward. Write a mathematical formula showing a player’s probability of success, varying with the distance of the grid lines.

I tried to solve this through one method and it ended up being completely wrong, I'm completely stuck, could anyone provide help on this?

 

[Deleted member 4993]

Here is a relevant excerpt:

In this new carnival game, square grids are drawn on the ground. The distance between lines is d mm. Players would throw toonie coins 28mm of diameter into the grid (of very large size). If the coin touches or crosses any line, they lose the coin; if it does not touch any line, they get a reward. Write a mathematical formula showing a player’s probability of success, varying with the distance of the grid lines.

I tried to solve this through one method and it ended up being completely wrong, I'm completely stuck, could anyone provide help on this?

Please share your "incorrect" work with us - so that we know where to begin to help you.

 

[mikeras]

I took the area of a square with the same length sides as the diameter of the coin and divided it by the area of a grid square.

area of square/area of grid square = probability of winning the game.

However, as the grid distance increases, the player should be get a higher win percentage, but based on the formula above the trend is opposite.