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: an engineer undertakes a project to build a road 10 km long in 150 days and employs 30 men for the purpose . after 50 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 ) 22 , b ) 30 , c ) 15 , d ) 18 , e ) 20
[A]: b

[Q]: Problem: the distance between 2 cities a and b is 1000 km . a train starts from a at 11 a . m . and travels towards b at 100 km / hr . another starts from b at 12 p . m . and travels towards a at 150 km / hr . at what time do they meet ?
Options: a ) 11 am . , b ) 12 p . m . , c ) 3 pm . , d ) 4 p . m . , e ) 1 p . m .
[A]: d

[Q]: Problem: train a leaves the station traveling at 30 miles per hour . two hours later train leaves the same station traveling in the same direction at 42 miles per hour . how many miles from the station was train a overtaken by train b ?
Options: a ) 150 , b ) 170 , c ) 190 , d ) 210 , e ) 230
[A]:
d