Question: Anthony keeps a bottle of vinegar in his cupboard for 2 years. Each year 20% of the vinegar evaporates. What percent of the vinegar is left after 2 years? Think carefully first, then make a decision:
First find what percent of the vinegar is still in the bottle after each year: 100% - 20% = 80%. Then multiply the amount of vinegar left after one year by the percentage left after each year to find how much is left after 2 years: 80% * 80% = 64%. So the answer is 64.