Down the Babbling River
Some family and friends have asked you to plan an end-of-the-summer getaway. A
rafting company has agreed to take your group down the Babbling River. (It's actually a
little smaller than a river, more like a brook.) The rafting company has given you specific
details as to how much weight each raft can hold. A raft can safely carry the weight of 24
babies. As everyone knows, the weight of 12 babies is exactly equal to the weight of 4
kids; the weight of 6 kids is equal to the weight of 3 adults.
What is the fewest number of rafts needed for a trip with 11 adults, 5 kids, and 21
babies?