Find the equivalent resistance and the current in each resistor

The equivalent resistor is 3.00Ω

Explanation:

The resistors 1.00Ω and 3.00Ω are in serie. So, the equivalent resistor in that branch the sum of both which is 4.00Ω. The same way to the resistors 7.00Ω and 5.00Ω, the equivalent resistor in that branch is 12.00Ω.

Now, both 4.00Ω and 12.00Ω now are in parallel. Solving 1/Rtotal=1/4.00Ω+1/12.00Ω=3.00Ω

Now, lets calculate the current in each resistor. As we saw before the equivalent resistor is 4.00Ω and 12.00Ω in each branch. The voltage of the source is fully present in both branch. Solving by using Ohm's Law to each equivalent resistor.

For the 4.00Ω equivalent resistor branch

I=V/R=48.0V/4.00Ω=12A

For the 12.00Ω equivalent resistor branch

I=V/R=48.0V/12.00Ω=4A

it has to be b, about 97 percent.