In a crossword puzzle 10 words are to be guessed of which 5 words have each an alternative solution also. Number of possible solutions is

out of 10 words 5 words can be guessed in 1 way.

                     and 5 words can be guessed in 2 ways.

$\begin{array}{rcl}\mathrm{Number} \mathrm{of} \mathrm{possible} \mathrm{answers} & =& 1^5\times 2^5\\ & =& 32\end{array}$