Jan spends part of her year as a member of a gym. She then finds a better deal at another gym, so she cancels her membership wit
h the first gym after x months and spends the rest of the year, y months, with the second gym. The membership to the first gym costs $60 per month, while the membership for the second gym costs $50 per month. If she ended up spending a total of $660 over the course of the year, how much time did she spend at each gym?
For every 3 zinc there would be 19 copper, and for every 19 copper there would be 3 zinc. There are 741 copper, so there would be 741 * 3 / 19 zinc, which turns out to be 117 zinc.
