You probably answered computer* OR comput* and these are both correct. Technically speaking, comp* is also correct, but see the answer to Exercise 3 below for more detail on this option.
The main problem that you might encounter using truncation is illustrated using the example comp* from above. If you search with the truncated keyword comp*, the search will find all of the words above, related to computers, as well as:
comprehension, company, compensation, comparison, comparative, companion, etc.
The rule of thumb when using truncation symbols is to truncate as far back in the word as you can, but not so far back that you will start to retrieve unrelated words, as in the comp* example. In some cases, this means you will not be able to truncate very far back in a word at all.
