Use the following general linear demand relation:

Qd$=1005$P$+0\mathrm{.}004$M$5$PRQd$=1005$P$+0\mathrm{.}004$M$5$PR

where P is the price of good X$,$ M is income, and PRPR is the price of a related good, R$.$ Income is $$80,000,$ and the price of the related good is $$40.$ Also let consumers' tastes change so that consumers now demand $100$ more units at each price. When the price of the good is $$50,$ how many units of the good are demanded?

Multiple Choice

$70$

$200$

$220$

$100$

None of the choices is correct.