A ship sails out to a mark at the rate of 18 kmph. and sails back at the rate of 14 kmph. The average rate of sailing is ?  Choose the correct choice from the following answers:
A) 5 km/hr
B) 12 km/hr
C) 16 km/hr
D) 25 km/hr
E) None
Answer   Average = ( 2uv / u +v ) km/hr   = ( 2 x 18 x 14 ) / (18 +14 ) km/hr.   = 16 km/hr.   16 km/hrorrect Option: 16 km/hr
<result>C</result>
A ship sails out to a mark at the rate of 18 kmph. and sails back at the rate of 14 kmph. The average rate of sailing is ?