Answer:
262.12367 mph
Explanation:
[tex]V_a[/tex] = Velocity of air
[tex]V_p[/tex] = Velocity of plane
Distance to travel = 512 km
Total time taken = 4 hours
So,
[tex]\frac{512}{V_p-22}+\frac{512}{V_p-12}=4\\\Rightarrow 512\left(V_p+12\right)+512\left(V_p-22\right)=4\left(V_p-22\right)\left(V_p+12\right)\\\Rightarrow 4V_p^2-1064V_p+4064=0[/tex]
Solving this quadratic equation we get,
[tex]V_p=\frac{-\left(-1064\right)+\sqrt{\left(-1064\right)^2-4\cdot \:4\cdot \:4064}}{2\cdot \:4}, \frac{-\left(-1064\right)-\sqrt{\left(-1064\right)^2-4\cdot \:4\cdot \:4064}}{2\cdot \:4}\\\Rightarrow V_p=262.12367, 3.87[/tex]
So, velocity of boat in plane without wind is 262.12367 mph