There is a 12v supply which is met with a series resister (R3) of 4 ohms, which is then followed by 2 parallel resister (R1) with 10 ohms & (R2) with 40 ohms, the current is 1A.

Can someone help explain the following:

1. How the 1A is worked out?

2. How the voltage passing through each resister is worked out?

3. How the overall resistance for the circuit is worked out?

Any help would be great.

Many Thanks

Greg