So looking at the circuit, e represents the battery. If we look at the battery more closely, the larger line represents the + side and the smaller end of the battery represents the - side. Positive charge flows from the positive end to the negative end around the circuit, and electrons flow in the opposite direction. So with that said, charge will leave the battery on the positive end and flow through the resistor labeled R1. We want to know the current through the resistor. Using V=IR, we know the voltage of the battery which is e, and we know resistance=R1 so plugging those in, e=I*R1, solve for I we get e/R1.
