Answer
The new quantity per week is 940 plates. The new revenue is \$20,680.
Work Step by Step
$\Delta\ qty=\Delta\ price\times E_d$
$\Delta\ qty=10\times0.6$
$\Delta\ qty=6\%$
The new quantity is
$1000-(1000\times6\%)=1000-60=940$
The new price is
$20+(20\times10\%)=20+2=22$
The new revenue is
%940\times22=20680$
