The equivalent ratio is 3/4.
Answer:
Step-by-step explanation:
Let x represent the speed of the first ferry.
Consequently, the second ferry's speed is x-5, as it travels 5 miles per hour slower.
The time taken by the first ferry is calculated as distance divided by speed = 
The time taken by the second ferry equals
.
Since the second ferry departs one hour earlier, the times differ by 1 hour.

The speed cannot be negative.
Thus, the speed of the first ferry is determined to be 18.5 mph,
and for the second, slower ferry, it equals 13.5 mph.