Page 161 - NUMINO Challenge_B2

Answer
Key

Type 11-1 Shortest Paths on Circles p.96~p.97 3 A111

1 12 3 4
14
21 1 3 6 10 1 1
3 B
1 2 3C

There are 10 shortest paths from A to B.
There are 3 shortest paths from B to C.
Therefore, there are 10 3 30 shortest paths
from A to C through B.

Problem solving

4 paths 11 4 10 20 35 Exit
3 6 10 15
1 2 34 5
1 11 1
Entrance

There are 35 shortest paths.

Problem solving 2 Entrance 1 1 Entrance 1
2 3
1 3 3 9 ways 1 11 2
2 Since there are 4 ways to go from A to
A 1 6 1 4
B and 2 ways to go from B and C, the B 3 2
number of paths from A to C is 4 2
8 shortest paths. Figure A : Figure B :

6 shortest paths 4 shortest paths

C p.100~p.101
Creative Thinking

Type 11-2 Shortest Paths in a Classroom p.98~p.99 1 You can go from A to C either by A B C or
1 Lisa
A C. There are 3 ways to go from A B and 2
Jane ways from B C; therefore, there are 3 2 6
ways to go from A B C. Also, there are 2
ways to go from A C. Therefore, there are
6 2 8 paths from A to C.

2 Lisa 20 10 4

10 6 3 1
1

4 32
1

1 1 1 Jane

There are 20 shortest paths.

NUMINO Challenge B2