[wail_poet]

when K is on B the wire cancels resistor no. 3
so Rtot = V/I = 6/2 = 3 ohms
R1 + R2 = 3 so R1 = 1 ohms
use info in equation #1
1 + 2 + R3 = 6 so R3 = 6 ohms
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