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'.

Problem: buses a and b start from a common bus stop x . bus a begins to travel in a straight line away from bus b at a constant rate of 20 miles per hour . one hour later , bus b begins to travel in a straight line in the exact opposite direction at a constant rate of 80 miles per hour . if both buses travel indefinitely , what is the positive difference , in minutes , between the amount of time it takes bus b to cover the exact distance that bus a has covered and the amount of time it takes bus b to cover twice the distance that bus a has covered ? 
Options: a ) 36 , b ) 72 , c ) 132 , d ) 144 , e ) 180
c

Problem: a train 100 m long can cross an electric pole in 20 sec and then find the speed of the train ? 
Options: a ) 19 kmph , b ) 18 kmph , c ) 72 kmph , d ) 17 kmph , e ) 91 kmph
b

Problem: the sector of a circle has radius of 20 cm and central angle 135 o . find its perimeter ? 
Options: a ) 91.5 , b ) 87.1 , c ) 91.7 , d ) 91.3 , e ) 91.1

b