How to find Formula of compound formed by A,B and C if their oxidation no. Is given

Let`s take A=Hydrogen(H),B=Sulphur(S),C=Oxygen(O) having oxidation states +1,+6,-2 respectively. Then net +ve charge=7 and net -ve charge =2. If the compound is neutral then +ve charge should be equal to -ve charge. As we can see that negative charge can be a multiple of 2 only => positive charge should also be a multiple of 2 for which we have to add either H or S so that +ve charge can become a multiple of 2 as well as we should keep in mind that we have to take it to its minimum +ve oxidation state. Therefore when we will add one more H then +ve charge will become +8. For negative charge to be equal, we will have to add 3 more O. Therefore total number of H becomes 2,S remains 1 and O becomes 4. Therefore the compound becomes H2SO4. Hope it helps.Best of luck:)