The amount of resistance, y, in a circuit varies inversely to the current, x, in the circuit. When 10 ohms of resistance are used in the circuit, 12 amperes of current are present. When 5 ohms of resistance are used in the same circuit, 24 amperes of current are present. How many ohms of resistance are used in the circuit when 15 amperes of current are present? Round your answer to the nearest tenth, if necessary.

7.5 ohms
8 ohms
50 ohms
120 ohms