2. Well if one out of 5 answers is correct, the odds of randomly guessing the correct answer are $\displaystyle \frac{1}{5}$ and the odds of randomly guessing an incorrect answer are $\displaystyle 1-\frac{1}{5}=\frac {4}{5}$
So use multiplication, the first two must be wrong so $\displaystyle \frac{4}{5}*\frac{4}{5}=\frac{16}{25}$