A) HD Headphones. x=110 x=$70 ea 110×70=$7,700 for HD Headphones 10,000-7,700=2,300 left y×w=2,300 for basic headphones My guess, 230 basic headphones for $10 each
b) Basic headphones y×w 55×20=$1,100 2,000-1,100=900 HD Headphones x×z=900 x=10,z=90 10×90=900 (I'm assuming that the price per item is higher due to the smaller quantity.