A 10x10 grid of panels lay on the floor, and 5 of the 100 panels have magical gold coins randomly spread throughout the grid. Of the 5 panels, there is a 50% chance that it will have a magical gold coin under it when checked. This will repeat until the coin is found. This probability doesn't change as attempts to check increase. Once a gold coin has been found, it is not replaced. What is the minimal amount of times one should check each panel to maximize goin coins while minimizing time?

Time limit: 200 seconds
Time to check a panel: 1.5 seconds

Question

A 10x10 grid of panels lay on the floor, and 5 of the 100 panels have magical gold coins randomly spread throughout the grid.  Of the 5 panels, there is a 50% chance that it will have a magical gold coin under it when checked.  This will repeat until the coin is found. This probability doesn't change as attempts to check increase.  Once a gold coin has been found, it is not replaced.  What is the minimal amount of times one should check each panel to maximize goin coins while minimizing time?

Time limit: 200 seconds
Time to check a panel: 1.5 seconds