What is the current in a parallel circuit which has two resistors (17.2 ohms and 22.4 ohms) and a power source of 6.0 volts?

We need to first find an equivalent resistance across the parallel circuit. that is found by the following equation

1/R1 + 1/R2 + ... = 1/Re

So ...

1/17.2 + 1/22.4 = 1/Re

0.1021 = 1/Re

Re = 9.792 Ohms

Now use the Voltage equation V = IR

6 = I * 9.792

I = 6/9.792 = 0.613 Amps (or the current)