A boat goes 112 km downstream and comes back to the starting point in 11.5 hrs. If the speed of the current is 9 km/hr, then the speed (in km/hr) of the boat in still water is?

23 km/hr

Let the speed of boat = U km/hr

ATQ,

       \(\frac{112}{U+9}\) + \(\frac{112}{U-9}\) = 11.5

Note :- Go with the options to satisfy the equation

          U = 23 km/hr satisfies the condition