To determine how many of each type of book Santiago bought, we would need additional information about the types of books he purchased. For example, if we know how many types of books there are and the distribution of each type (e.g., fiction, non-fiction, textbooks, etc.), we could set up equations to solve for the number of each type.
If you provide specific details about the types of books or any constraints regarding the quantities of each type, I can help you formulate a solution!