Try to use these formula to solve the problem . Answer is 3
But sir the circuit which you have drawn the polarity of e2 and E3 is same so why it's not substracted
See in series circuit, oppoiste terminals should be connected(positive terminal to negative terminal and viceversa) ,otherwise -E will come
In parallel circuit, same terminals have to be connected(positve terminals of all battery connected together and negative terminals of all batteries connected together), otherwise -E will come
After simply the series circuit got the simple parallel combination but the answer come by the substraction of emf even they are of same polarity in parallel
My doubts has got cleared
Than you so much sirk