A) The mexican subsidary of ThermoMaster manufactures an indoor-outdoor thermometer.Management estimates that the profit (in dollars) realizable by the company for the manufacture and sales of x units of thermometers each week is P(X)= -0.001x^2+8x-5000. Find the intervals where profit is increasing.

B)Consider a college student who works from 7 pm to 11 pm assembling mechanical components. The number N of componets assembles after t hours is given by the following function. At what time is the student assembling components at the greatest rate?