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: what is the maximum number of pieces of birthday cake of size 2 ” by 2 ” that can be cut from a cake 20 ” by 20 ” ? 
Options: a ) 5 , b ) 100 , c ) 16 , d ) 20 , e ) 25

A: b
****
Q: Problem: a train is 360 meter long is running at a speed of 30 km / hour . in what time will it pass a bridge of 140 meter length ? 
Options: a ) 87 , b ) 69 , c ) 60 , d ) 72 , e ) 21

A: c
****
Q: Problem: a boat can travel with a speed of 22 km / hr in still water . if the speed of the stream is 5 km / hr , find the time taken by the boat to go 81 km downstream 
Options: a ) 5 hours , b ) 4 hours , c ) 3 hours , d ) 2 hours , e ) none of these

A:
c
****