8% of 1500=0.08*1500=120 tables scrapped leaving 1380 good tables. 92% of the tables were good.
Ethan sold 60% of the good tables=0.60*1380=828 tables.
So the number donated=1380-828=552. We could have worked this out by saying that Ethan donated 100-60=40% of the tables, 0.40*1380=552.
The percentage donated=552/1500=0.368=36.8%.
This is the same as 0.92*0.40=0.368=36.8%.