A ship sails out to a mark at the rate of 19 kmph. and sails back at the rate of 13 kmph. The average rate of sailing is ?	Choose the correct option.
A) 15 km/hr  B) 12 km/hr  C) 12.5 km/hr  D) 25 km/hr  E) None
Answer   Average = ( 2uv / u +v ) km/hr   = ( 2 x 19 x 13 ) / (19 +13 ) km/hr.   = 15 km/hr.   Correct Option: 15 km/hr
<result>A</result>
A ship sails out to a mark at the rate of 19 kmph. and sails back at the rate of 13 kmph. The average rate of sailing is ?