Given: Two resistors with resistances R1=5ohm and R2=10ohm, V=6volt
(a) For minimum current these two should be connected in series. For maximum current these two should be connected in parallel.
Total resistance = 5+10 = 15ohms
Therefore total current drawn = V/R = 6/15 = 0.4amps
Total resistance R is given as 1/R=1/R1+1/R2
Therefore total current drawn by the circuit = V/R = 6/(10/3) =1.8amps.