45-40 = 5 (km) ................................................................................................................................................................

40÷5=8 (hours)

8+ 1 = 9 (hours)

A: It takes nine hours for the bus to transfer from A to B. ..

Or comprehensive calculation: 40 ÷ (45-40)+ 1.

=40÷5+ 1

=9 hours

A: It takes nine hours for the bus to transfer from A to B. ..