Answer: pay an additional 12% of the original cost as interest
Explanation:
The simple interest rate for a rainforest tour paid after 3 months is 12%. This means that if you pay the full amount of the tour after 3 months, you will pay an additional 12% of the original cost as interest. For example, if the original cost of the tour is $100, after 3 months, you will need to pay $112, which includes the original cost of $100, plus $12 in interest.