How much power is the 20ω resistor dissipating?
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the 10ω resistor in the figure (figure 1) is dissipating 35 w of power.
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refer to picture

The power dissipated by a resistor is given by:
(1)
where I is the current through the resistor and R is the resistance.

We are told that the resistor of  dissipates 35 W of power. By rearranging the previous equation (1), and by using these data, we can find the current flowing through the resistor of :


This is the current flowing in the left branch of the circuit: we need to find the current flowing in the right branch, .
The equivalent resistance on the left branch is the sum of the two resistances, since they are in series:

We know that this resistance is in parallel with the resistor on the right, , so they have same potential difference:

which can be rewritten, by using Ohm's law:

Rearranging the equation, we find the current through the right branch:


And now we can find the power dissipated through the resistor on the right:

The center is basically the heart of it

The answer is a.  i hope this