At the End of December 31, 2013 Fiscal Year, JB

At the end of December 31, 2013 fiscal year, JB had the following assets: $\begin{array}{|l|l|l|l|}\hline {\text { Estimated }} \\\hline \text { Asse } & \text { Cost } & \text { Residual Value } & \text { Useful Life } \\\hline \text { A } & \$ 16,400 & \$-0- & 4 \\\hline \text { B } & 10,000 & 400 & 3 \\\hline \text { C } & 35,000 & 2,100 & 7 \\\hline\end{array}$
Because the assets are dissimilar, composite amortization is used.
(a) The composite amortization rate is ______% (round to the nearest whole percent).
(b) Assuming amortization is based on the ending balances, amortization expense for 2013 would be $____________________.
(c) If asset B is sold at the beginning of 2014 for $8,000 cash, what gain or loss should JB recognize? $____________________.