Question

a resistance of 5 ohm is connected in series with a parallel combination of a number of resistors each of 5 ohm if the total resistance of the combination is 6 ohm how many resistor are in parallel

Answer 1

In series the R=r1+r2+......
In parallel 1/R=1/r1+1/r2+......
So the parrelal effective resistance should be 1 so the are 5 resister of 5 ohm each

Answer 2

Resistance of resistor connected in series = 5 ohm
Total resistance = 6 ohm
The required resistance from parallel case is 1 ohm
So,
Number of 5 ohm resistors = 5
{Since 5/5 ohm=1 ohm}
Then the total resistance will be 5+1 = 6 ohm