A history teacher gives a 20 question T-F exam. In how many different ways can the test be answered if the possible answers are T or F, or possibly to leave the answer blank?

3 answers

I THINK 60 (not sure)
2 choices for each answer gives 2^20 = 1,048,576

including blanks, that's 3 choices for each question, or 3^20 = 3,486,784,401
100