Question

There are three resistance,each having value of 3ohm. How do the combine so that equivalent resistance becomes 3ohm​

Answer 1

Answer:

Each resistor has a value of three Ohms and when combined, their sum is equal to 3 Ohms.

And here’s the second:

Three resistors (whose values are unknown) are added and their sum is equal to 3 Ohms.

I don’t see a way that the first interpretation would work because three resistors of 3 Ohms each in parallel yields 1 Ohm. Two in parallel and one in series would yield 4.5 Ohms. And two in series and one in parallel with both would yield 2 Ohms.

The second interpretation does work. It’s simply an exercise in algebra. Here’s the formula you need to solve it:

It simply says that the total resistance of parallel resistors is the inverted sum of all resistors inverted. Or, if this is too complicated for you, then you can use this formula:

When you find the answer with the first two resistors, use that value with the third resistor to find the final answer.