In this task, you need to answer the given multiple-choice question on the physics. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

[Q]: Problem: a river boat leaves silver town and travels upstream to gold town at an average speed of 6 kilometers per hour . it returns by the same route at an average speed of 5 kilometers per hour . what is the average speed for the round - trip in kilometers per hour ? 
Options: a ) 5.5 , b ) 7.1 , c ) 7.2 , d ) 7.0 , e ) 8.0
[A]: a


[Q]: Problem: annie and sam set out together on bicycles traveling at 15 and 12 km per hour respectively . after 40 minutes , annie stops to fix a flat tire . if it takes annie 30 minutes to fix the flat tire and sam continues to ride during this time , how many minutes will it take annie to catch up with sam assuming that annie resumes riding at 15 km per hour ? 
Options: a ) 20 , b ) 40 , c ) 60 , d ) 80 , e ) 100
[A]: d


[Q]: Problem: a train running at a speed of 36 km / h passes an electric pole in 15 seconds . in how many seconds will the whole train pass a 380 - meter long platform ? 
Options: a ) 47 , b ) 49 , c ) 51 , d ) 53 , e ) 55
[A]:
d