Question

Felicia is a contractor. She has a railway project to finish. Felicia puts 40 workers where they
can lay a section of railway in 120 days. If Felicia wants to reduce the time taken by 20 days, how many
additional workers should be hired in order to finish the task on time?

Answer 1

Answer:

Total unit of work = 20 men x 30 days = 600 Man-Days (MD)

So, 20 men working for 1 day will do 1/30 part of the job.

So, 1 man working for 1 single day will do 1/(30*20) = 1/600 part of the job.

Now, let us assume that 5 people leave after x days.

So, as per the question, 20 men worked for x days and 15 men worked for (35-x) days.

So, to form an equation,

20x/600 + 15(35-x)/600 = 1

=> 20x + 525 - 15x = 600

=> 5x = 75

=> x = 15

Answer 2

Answer:

divide 40 by 120 and the answer will come