Answer:
Use one 3 ohm resistor and one 6 ohm resistor in paralel
Explanation:
The equation to solve two resistor in paralel:
[tex]R=({\frac{1}{R1}+\frac{1}{R2} } )^{-1}[/tex]
For the case of only two resistor:
[tex]R=\frac{R1*R2}{R1+R2}[/tex]
Doing this for the 3 and the 6 ohm resistor plus the 48 ohm:
[tex]R=\frac{3*6}{3+6}+48=50[/tex]