Question 7
The diagram shows parts of a city where the lines are roads. Charles walks from point X to point Y along the roads without ‘backtracking’ (i.e. he can only walk downwards or to the right in the diagram below). How many ways can he walk from X to Y?
A. 54
B. 55
C. 56
D. 57
E. None of the above
**Editorial note for this self-study exercise:** Enter the number of routes, rather than an option letter.
A. 54
B. 55
C. 56
D. 57
E. None of the above
**Editorial note for this self-study exercise:** Enter the number of routes, rather than an option letter.