An aeroplane covers a certain distance at a speed of 240 kmph in 5 hours. To cover the same distance in $$1\frac{2}{3}$$ hours, it must travel at a speed of:

$$\eqalign{ & {\text{Distance}} = {240 \times 5} = 1200\,{\text{km}} \cr & {\text{Speed}} = \frac{{{\text{Distance}}}}{{{\text{Time}}}} \cr & {\text{Speed}} = \frac{{1200}}{{ {\frac{5}{3}} }}\,{\text{ km/hr}}\, \cr & \left[ {{\text{We}}\,{\text{can}}\,{\text{write}}\,1\frac{2}{3}\,{\text{hours}}\,{\text{as}}\,\frac{5}{3}\,{\text{hours}}} \right] \cr & \therefore {\text{Required}}\,{\text{speed}} \cr & = {1200 \times \frac{3}{5}} \,{\text{ km/hr}} \cr & = 720\,{\text{ km/hr}} \cr} $$