JEE PHYSICS MCQ: MECHANICAL PROPERTIES OF FLUIDS

A plane of mass $3250 {~g}$ is in level flight at a constant speed and each wing has an area of $25 {~m}^2$. During flight the speed of the air is $216 \,{kmh}^{-1}$ over the lower wing surface and $252 \,{kmh}^{-1}$ over the upper wing surface of each wing of aeroplane. Take density of air $=1 \,{kgm}^{-3}$ and $g=10 {~ms}^{-2}$.
If a plane is in level flight with a speed of $360 \,{kmh}^{-1}$ then the fractional increase in the speed of the air on the upper surface of the wing relative to the lower surface is