Composition of functions​

The number of fish in a lake can be modeled by the exponential regression equation y=14.08 x 2.08^x where x represents the year

The power generated by an electrical circuit (in watts) as a function of its current c (in amperes) is modeled by p(c)= -15c(c-8) what current will produce the maximum power?

Sade bought 21 1/2 lb. of ground beef. he used 1/4 of the beef to make tacos and 2/3 of the remainder to make quarter-pound burgers. how many burgers did he make?