In the wake of the 2008 financial crisis, bank failures started spiraling upward. The number of bank failures peaked in 2010 at 157 . Thereafter, the number of bank failures began to fall sharply. The number of bank failures from 2010 through 2012 is described by the function $$f(t)=157 e^{-0.55 t} \quad(0 \leq t \leq 2)$$ where $t$ is measured in years, with $t=0$ corresponding to 2010 .
a. How fast was the number of bank failures dropping in $2011 ?$
b. If the trend continued, how many bank failures were there in $2013 ?$