Sally likes soda very much. At the local convenience store, for 5 empty soda bottles she receives a full bottle.
As part of a local recycling initiative, she manages to collect 77 empty bottles.
How many bottles of soda will she be able to drink in total?
Answer: 19 bottles.
From the initial 77 bottles, she receives 15 full bottles (with 2 spare empties). From the 17 empties, she receives 3 more full bottles (with 2 spare empties). From the 5 empties she receives one final full bottle.