Using Ohm's Law, V=IR, where:
V = Voltage
I = Current
R = Resistance
We have two wires with equal current, but different resistance. To make our lives easier, we will use only 1 Amp of current:
V1 = (1A)(3.0Ω) = 3.0 Volts
V2 = (1A)(2.5Ω) = 2.5 Volts
From this simple calculation, we can conclude that the wire with the 3Ω resistance has a greater voltage.
Remember, resistance impedes the flow of electrons, current.
When you get deeper into this, depending on the specific circuit, these parameters may change. But always use Ohm's Law if you are unsure.