I have a square field which is exactly one hectare (100 m × 100 m). On Monday I was surprised to find 4 mushrooms growing in a 1 m square formation, in the centre of my field. On Tuesday the group of mushrooms had expanded to 16, which were all 1 m apart.
When I looked at the group of mushrooms today (Wednesday), it had expanded to 36.
If the area covered by mushrooms continues to expand at this rate, how many days (including today) will it be until my field is covered in mushrooms?