An electronics store sells an average of 60 entertainment systems per month at an
average of $800 more than the cost price.
For every $20 increase in the selling price,
the store sells one fewer system. What
amount over the cost price will maximize
profit?
if

A33 gram sample of a substance that's used to detect explosives has a k-value of 0.1473. n = noekt no = initial mass (at time t = 0) n = mass at time t k = a positive constant that depends on the substance itself and on the units used to measure time t = time, in days