Consider an oral antibiotic that is given at breakfast lunch and dinner. The oral doses are $250$mg each and are taken at $7$am$,12$pm and $6$pm$.$ kel $=0\mathrm{.}15$ hr$-1,$ ka $=2\mathrm{.}2$ hr$-1,$ V$=30$L$,$ F$=1.$ Plot the drug concentration in the plasma as a function of time on linear axes for a $24$ hour period. What is the maximum drug concentration? At what time is this concentration achieved?