Answers and explanations:
1) A modification problem takes places when creating a database two different type of information is entered in the same chart row generating inaccuracy. The only form to solve this issue is creating a new row so each piece of information will be stored in one row particularly.
2) There are three (3) types of modification problems: the deletion problem (the single row containing information from different themes can be deleted losing data), the update problem (new information entered could lead to more inconsistency), and the insertion problem (similar to deletion, a new row can be inserted instead of the row causing problem but information will be missing).