Predict what the empirical formula for C5H10O5 will be?

The empirical formula is the simplest form of molecular formula and in this case we have C₅H₁₀O₅

as we can see that all elements can be divided by 5 to get the simplest form:

C₅H₁₀O₅ all divided by 5 to give CH₂O

So the empirical formula of this compound is CH₂O