By Newton's second law we have:
[tex]a=\frac{F}{m}[/tex]then, originally we have:
[tex]\frac{F}{m}=6[/tex]If we tripled the force and halved the mass then we have:
[tex]\frac{3F}{\frac{1}{2}m}=\frac{3}{\frac{1}{2}}\cdot\frac{F}{m}=6(6)=36[/tex]Therefore the new acceleration is 36 meters per second per second.