I believe I forgot to divide first.
So it's probably 23.
27 - 4 = 23
Here is the problem as it appears.
http://img241.imageshack.us/img241/8585/prob1ej5.png
then it is ambiguous and you are free to make a choice about where you
put the brackets to make it unambiguous. But you should state what you
have done. I would interepret it as 27 - [256/(4^3)], as that makes
everything nice and round.
So go for an answer something like:
Assume that:
27 - 256 : 4^3
means:
27 - [256 : (4^3)]
which is:
27 - [256/(4^3)] = 27 - 256/64 = 27 - 5 = 23.
If you need a justification for making this assumption it can be:
" ':' is a variant form of division '/', and in most conventions for
the precedence of arithmetic operators '/' takes precedence over
'+' and '-' "
RonL