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: when the perimeter of a regular polygon is divided by 5 , the length of a side is 25 . what is the name of the polygon ? what is the perimeter ?
Options: ['a ) 125', 'b ) 126', 'c ) 127', 'd ) 128', 'e ) 129']
[A]: a

[Q]: Problem: a hollow iron pipe is 21 cm long and its external diameter is 8 cm . if the thickness of the pipe is 1 cm and iron weights 8 g / cm cube , then find the weight of the pipe .
Options: ['a ) 3.696 kg', 'b ) 3.686 kg', 'c ) 2.696 kg', 'd ) 2.686 kg', 'e ) none of these']
[A]: a

[Q]: Problem: a train 560 m long , running with a speed of 63 km / hr will pass a tree in ?
Options: a ) 15 , b ) 16 , c ) 17 , d ) 28 , e ) 32
[A]:
e