Question 5
Some adults and children are on one side of a river with only one boat. Everyone can row. The boat can carry no more than:
- 2 adults; or
- 2 children accompanied by 1 adult; or
- 4 children.
A crossing from one bank to the other counts as one trip.
Editorial illustration: A means adult and C means child.
(a) What is the least number of trips needed to get 5 adults and 10 children across?
(b) What is the least number needed for 10 adults and 10 children?
(c) What is the least number needed for 20 adults and 20 children?
- 2 adults; or
- 2 children accompanied by 1 adult; or
- 4 children.
A crossing from one bank to the other counts as one trip.
Editorial illustration: A means adult and C means child.
(a) What is the least number of trips needed to get 5 adults and 10 children across?
(b) What is the least number needed for 10 adults and 10 children?
(c) What is the least number needed for 20 adults and 20 children?