The adventurers learn that the mob boss demands a minimum of 12 watches and 30 rings to be sold every day, and has figured out how to get what he wants while paying his two workers the least possible amount (while still honouring their agreed-upon hourly wages). While Lara and Harrison can't tell how many hours each worker spends selling the jewelry, or how many items they actually sell each day.

How long do the two workers sell jewelry each day?

Without knowing how many hours each worker spends selling jewelry or how many items they actually sell, it is not possible to determine how long the two workers sell jewelry each day.

To determine how long each worker sells jewelry each day, we need more information. The number of watches and rings sold daily is provided, but without knowing how many hours each worker spends selling jewelry or how many items they sell each day, we cannot calculate the specific time each worker spends selling.

However, we can explore some scenarios to understand the possible time distribution. Let's assume there are two workers, Lara and Harrison, and they work the same number of hours each day.

1. Scenario 1: Lara and Harrison work an equal number of hours and sell an equal number of items each day.
In this case, if each worker sells half of the minimum demand, Lara would sell 6 watches and 15 rings, while Harrison would sell 6 watches and 15 rings as well. This would result in a total sale of 12 watches and 30 rings, meeting the mob boss's demand.

2. Scenario 2: Lara and Harrison work an equal number of hours, but one worker sells more items than the other.
Since we don't have specific information about how many items each worker sells, we can't determine the exact time distribution in this scenario.

In conclusion, without additional information about the number of items each worker sells or the specific hours they work, we cannot determine how long each worker spends selling jewelry each day.