Amount of Joelle earns per hour is $7.50
Amount that Joelle earns during extra hours =1 1/2 or 7.5=3/2*7.5=11.25
thus given that she worked for 42 hours, the total amount earned will be as follows:
amount earned in regular hours=40×7.5=$300
amount earned overtime=11.25×2=22.5
Thus the total amount earned:
300+22.5
=$322.5
the total amount earned during that week is $322.5