You will be given a definition of a task first, then some input of the task.
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: an engineer undertakes a project to build a road 10 km long in 15 days and employs 30 men for the purpose . after 5 days , he finds only 2 km of the road has been completed . find the ( approximate ) number of extra men he must employ to finish the work in time .
Options: a ) 15 , b ) 20 , c ) 25 , d ) 28 , e ) 30
Output:
e