Rob bought a tennis racket for $54.50 and some tennis balls for $9.99. He had a coupon for 30% off his total purchase. There was a 5.5% sales tax on his purchase. How much change did he receive if he handed the cashier $50?

2.75

Step-by-step explanation:

area of part 1:

a1=base*height/2=(8+2)*(8-2-2-1)/2=10*3/2=15 ft^2

area of part 2:

a2=length*width=(8+2)*1=10 ft2

area of part 3:

a3=length*width=8*2=16 ft2

total shaded area : a1+a2+a3=41 ft2

total area of the reactangle : a=16*8=128 ft2

total area of the nonshaded region : 128-41=87 ft2