Answer
30 rad, 7.5 mJ, 30 rem.
Work Step by Step
a. The RBE for fast neutrons is 10, so by equation 43.21, the equivalent dose in rad is $\frac{300rem}{RBE} =30rad$.
b. 30rad=$\frac{0.30J}{kg}$
$\frac{0.30J}{kg}(0.025kg)=7.5mJ$
c. If the RBE were 1.0, the 30 rad would correspond to 30 rem.