A crow takes 150second to fly from pole Ato pole B against a strong breeze blowing at 1.5m/s .Flying back from pole B to pole A with the breeze, it take just 114 second. How fast can the crow fly through still air?

Let the distance b/w poles be x m and the speed of crow in still air be y m/sec. Speed of crow against breeze =(y-1.5) m/src. " " " with " =(y+1.5) m/sec Applying formula, d=s×t In first case, x=(y-1.5)×150=150y-225 .....(1) In 2nd case, x=(y+1.5)×114=114y+171 .....(2) From equations (1) and (2), we get 150y-225=114y+171 or,150y-114y=171+225 or,36y=396 or, y=11 Hence the crow can fly with speed of 11 m/sec. through still air.