local model = Instance.new('Model')

model.Parent = game.Workspace

for j = 0, 9 do

    for i = 0, 9 do

        local part = Instance.new('Part')

        part.Parent = model

        part.Anchored = true

        part.Size = Vector3.new(7, 2,7)

        part.Position = Vector3.new(i * 10, 6, j * 10)

        local chance = math.random(1,100)

        if chance > 50 then

            part.CanCollide = false

            part.BrickColor = BrickColor.new('Really red')

        end

    end

end