A ship sails out to a mark at the rate of 23 kmph. and sails back at the rate of 16 kmph. The average rate of sailing is ?
Choose the correct answer.
A) 5 km/hr  B) 12 km/hr  C) 12.5 km/hr  D) 19 km/hr  E) None
Answer   Average = ( 2uv / u +v ) km/hr   = ( 2 x 23 x 16 ) / (23 +16 ) km/hr.   = 19 km/hr.   Correct Option: 19 km/hr
<result>D</result>
A ship sails out to a mark at the rate of 23 kmph. and sails back at the rate of 16 kmph. The average rate of sailing is ?