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'.

[EX Q]: Problem: cole drove from home to work at an average speed of 60 kmh . he then returned home at an average speed of 90 kmh . if the round trip took a total of 2 hours , how many minutes did it take cole to drive to work ? 
Options: a ) 66 , b ) 70 , c ) 72 , d ) 75 , e ) 78
[EX A]: c

[EX Q]: Problem: if the perimeter of a rectangular garden is 1800 m , its length when its breadth is 400 m is ? 
Options: a ) 500 , b ) 600 , c ) 700 , d ) 800 , e ) 900
[EX A]: a

[EX Q]: Problem: two pipes a and b can fill a tank in 20 and 30 minutes respectively . if both the pipes are used together , then how long it will take to fill the tank ? 
Options: a ) 10 mins , b ) 12 mins , c ) 15 mins , d ) 20 mins , e ) 30 mins
[EX A]:
b