In an electrical circuit, the current passing through a conductor varies inversely with the resistance. Suppose that when the current is
3 A (amperes), the resistance is
40 ohms. What is the current when the resistance is15ohms?

Question

In an electrical circuit, the current passing through a conductor varies inversely with the resistance. Suppose that when the current is 
3 A (amperes), the resistance is 
40 ohms. What is the current when the resistance is15ohms?

sooobored · Answer

Ohms law

V=IR
V- voltage
I- current (in Amps)
R- resistance ( in ohms)

sooobored · Answer

your question gives 2 cases

the first case, you have current and resistance
I= 3A
R=40 ohm

so you can calculate Voltage of the system

sooobored · Answer

once you have the voltage of the system, you can rearrange ohms law to calculate current for a resistance of 15 ohms$$I=\frac{V}{R}$$