A boat travels a distance of 54 km at uniform speed. If the speed of boat is increased by 3 km/hr, then it takes 3 hours less to cover the same distance. What is the original speed of the boat?

Correct option is D

Given:
Distance = 54 km
Increase in speed = 3 km/hr
Time difference = 3 hours
Formula Used:
Speed = Distance ÷ Time
Solution:
Let the original speed of the boat be x km/hr.
Time taken at original speed =$$\frac{54 }{x}$$ hours
Time taken at new speed = $$\frac{54}{x + 3}$$​ hours
According to the question:
​$$\frac{54 }{x} - \frac{54 }{x+3} = 3\\\frac{162}{x(x+3)} = 3\\x(x+3) = 54 \\\text{Now the value of x can be 6 km/hr}$$​​