Page 160 - NUMINO Challenge_B2

3 2 To draw paths that start from the same entrance

Sprouts Roses and finish at the same exit, there should be zero
odd-points. When you represent the town by
Entrance Sunflowers Dandelions Plant Exit dots and the bridges by lines, you will notice
(Exit) Exhibits (Entrance) that towns B and E are the odd-points.

Tulips Cosmos A
D BE
Problem solving
C
1
Therefore, when you draw a bridge that connects
Answers will vary. towns B and E, the person can cross every bridge
only once before returning to his town.
2 To make one-line drawing possible on a floor
A
plan from the entrance to the exit, each room E
should have an even number of doors.
Therefore, you need to remove the door that B
connects room A and room E. D

Entrance B C
A C
3
DE F
Answers will vary.

4 When you represent points A to K by dots and

the paths by lines, points G and I are the odd-
points. Therefore, the entrance and exit must be
at either point G or point I.

Exit

11 Number of Shortest Paths p.94~p.95

Creative Thinking p.92~p.93 Example 4, 3, 3, 12 3, 3, 7
2TryItAgain 3 6 shortest paths
1

Example 10 6 10, 6, 60

B1 1 1
12 3
13 6

C

Answer Key