यदि तन्मय तीन समान दूरियों को क्रमशः 2 किमी/घंटा, 3 किमी/घंटा और 4 किमी/घंटा की गति से तय करता है, तो पूरी यात्रा के दौरान उसकी औसत गति (किमी/घंटा में) ज्ञात कीजिए। (दशमलव के 2 स्थानों तक पूर्णांकित)

P takes 6 hours more than Q to walk 'm' km. If P doubles his speed, then he can make it in 2 hours less than Q. How much time (in hours) does P require to walk 'm' km?

A policeman spots a thief from a distance of 105 metres. The thief and the policeman travel at speeds of 90 km/h and 100 km/h respectively. How long will it take the policeman to catch the thief?