Question

show how would you join three resistor each of resistance of 9 ohm so that the equivalent resistance of the combination 1. 13.5 ii 6 ohm

Answer 1

1. to obtain total resistance 13.5 ohms

 Connect two resistors in parallel and one in series

2. to obtain 6 ohms 

Connect two resistors in series and one in parallel

Verification

1/R = 1/Ro + 1/R3
1/R = 1/18 + 1/9
1/R = 1+2/18
 1/R = 3/18

so, R = 6 ohms Verified     

Answer 2

1 in parellel and other in sereis to get 13.5 and 1 in series and rest in parellel to get 6
cool was ur answer right?