its an empirical formula stoichiometry problem so its like CxHyOz=H2O+CO2 u gotta balance the equation then use stoichiometry to find the mass for both 175 and 250. then u use that to find the right ratio of c, h, and o and add up the masses of those from the periodic table.
If u got a test on this i would reccomend memorizing how to set up a stoi......