Toán Lớp 7: 9. After a party, Jane washed half of the glasses, Alex washed half of the rest and then Sasha washed half of the remaining glasses. Th

Toán Lớp 7: 9. After a party, Jane washed half of the glasses, Alex washed half of the rest and then Sasha washed half of the remaining glasses. There were only three glasses left for David to wash. Half of the guests used one glass each and the other half of the guests used two glasses each. How many people were there at the party? A.8 B.16 C.18 D.24 E. 36