A policeman starts to chase a thief . When the thief goes 10 steps the policeman moves 8 steps . 5 steps of the policeman are equal to 7 steps of the thief . The ratio of the speed of the policeman and the thief is :

28 : 25

5 steps of Policeman(P) is equal to 7 steps of Thief(T)

i.e.   5P = 7T 

         P = \(\frac{7T}{5}\)

\(\frac{Speed\;of \; Police}{Speed\;of \; Thief}\)  =  \(\frac{8P}{10T}\)

 \(\frac{8\;×\;\frac{7T}{5}}{10T}\) = \(\frac{56}{50}\)

 Ratio of speed of Police : Thief =  28 :  25