MathDB

Towns

A

B

and

C

are connected with a telecommunications cable. If you for example want to send a message from

A

B

is assigned to either a direct line between

A

and

B

, or if necessary, a line via

C

. There are

43

lines between

A

and

B

, including those who go through

C

, and

29

lines between

B

and

C

, including those who go via

A

. How many lines, are there between

A

and

C

(including those who go via

B

4