The estimated monthly sales of Mona Lisapaint-by-number sets is given by the formula q =105ep −3p2/2,
where q is the demand in monthly sales and pis the retail price in yen.
(a) Determine the price elasticity of demand E when theretail price is set at 4 yen.
E =Â Â
Interpret your answer.
The demand is going  ? updown  by   % per 1% increase in price atthat price level. Thus, a large price  ? increasedecrease  is advised.
(b) At what price will revenue be a maximum? (Round your answer totwo decimal places.)
yen
(c) Approximately how many paint-by-number sets will be sold permonth at the price in part (b)? (Round your answer to the nearestinteger.)
paint-by-number sets per month
