Section B$//$type $2-$NL

DDF company has a maximum capacity of $2\mathrm{.}5$ million kilowatt$/$hour $($KWh$)$ of electric power available on a daily basis. The demand for power from its customers for high demand peak hours and low demand peak hours is determined by the following formulas:

High demand: $5\mathrm{.}8-0\mathrm{.}06ph0\mathrm{.}005pl$

Low demand: $3\mathrm{.}0-0\mathrm{.}11ph0\mathrm{.}008pl$

Where pl is the price for low demand and ph is the price for high demand.

Required: formulate and solve a nonlinear programming model to determine the structure $($ KWh $)$ that will maximize revenue.