## 219. Math Puzzle $8 / 83$

After evaluating satellite images from space, Soviet geologists have discovered a new deposit of 300 million tons of copper ore. It has a metal content of 5 percent. Every year, 10 percent of the reserves are mined.

How many tons of pure copper can be produced in total over 3 years?
In the first year, 30 million tons of ore are mined, in the second year 27 million, in the third 24.3 million. In total, 81.3 million tons. With a metal content of 5 percent, this amounts to 4.065 million tons of pure copper.