we know that
[volume of rectangular prism]=L*W*h
L= 6 in prism A
volume of rectangular prism A=6*w*h
L=6*(1/2)------> L=3 in prism B
volume of rectangular prism B=3*w*h
so
volume of rectangular prism B=[volume of rectangular prism A]/2
the answer is
Volume of B is 1/2 volume of A