Question 1: One of the main causes of European exploration in the 15th and 16th centuries was the search for new trade routes & luxury goods.
Question 2: Mercantilism impacted the American colonies by restricting the colonies' ability to trade with countries other than Britain.
Question 3: The impact of the discovery of the Americas on European exploration was all of the above (increased competition between European powers, expansion of the Atlantic slave trade, and introduction of new crops and animals to Europe).