每1.5m父子俩重叠一次,共留下7个脚印,1099/7=157,可知花坛周长为1.5*157=235.5m,则其直径为75m
设每箱装x个苹果,共有y个苹果:
42x=0.3y
85x+1540=y 可得x=28,y=3920