[5 marks]The function C(t)=K(eatebt), where a, b, and K are positive constants and b>a, is used to model the concentration in g/cm^3 of a drug t[0,10] days after its been injected into the bloodstream.

1. Given that K= 4, a= 11 and b= 13, determine the time at which the concentration of the drug is at its highest given that this occurs when C(t)=0. Results are to be rounded to 6 decimal places.
2. Use the result in part (a), find what the highest concentration the drug reaches in the bloodstream. Results are to be rounded to 2 decimal places.