Xiao Ming: 20÷5/8=32 copies
Xiaodong: 32+20=52 This second question: The cost of the first block: 72÷( 1+ 1/5)=60 yuan.
Part II Cost: 72×( 1- 1/5)=90 yuan.
72×2= 144 yuan
90+60= 150 yuan
150- 144=6 yuan
Answer 6 yuan at a loss.