A circuit has a current of 1.2 A. If the voltage decreases to one-third of its original amount while the resistance remains constant, what will be the resulting current?

I've got that the answer is 0.4A. This is because current = voltage:resitance

So, 1.2A=voltage:resistance

However, if you only have 1/3 of the voltage AND the resistance remains constant, the current will change proportionally and will also decrease by 1/3 to give you 0.4A

courtesy of the correction: the question asker