How does the mining mini-game work?

Question

Game development

The mining mini-game
will be a list of farms, bought a farm for 10,000 coins and it brings 200 coins every 5 minutes. but the farm may break. how it's done? Is there a time limit for it to break? What's the formula? If the farm is broken, it can be repaired, if it exploded, then it is impossible.

Answer 1

I would make the "half-life" of the farm and every n ticks explode with n/(2 * half-life in ticks) probability

Answer 2

You set the "explosion probability" to, say, 0.01 (1 is exactly an explosion) and once per game cycle (let's say you have 20 cycles per second) make the explosion probability equal to 0.01. Then it can be argued that in tech. For 5 seconds, the farm will be bombed with a 100% chance.
Did I explain clearly?

Answer 3

Is the chance of failure always the same? Causes and conditions of "explosion"? You can buy different farms by level, is it possible to upgrade? Are we supposed to come up with all the conditions for you?