The total cost of a bus ride and a ferry ride is $8.00. in one month, bus fare will increase by 10% and ferry fare will increase by 25%. the total cost will then be 9.25. how much is the current bus fare?

B + f = 8
where b is the current bus fare and f the current ferry fare.

1.10b + 1.25f= 9.25.              Replace f with 8- b:

1.10b + 1.25(8-b) = 9.25
Then:
1.10b-1.25b + 10 = 9.25, and so
-0.15b = -0.75.  Then b = -0.75 / (-0.15) = 5

The bus fare is current $5, and so the ferry fare is $3.