Question

A work is expected to be completed by 20 workers in 25 days. The work is started by 10 workers. Then,
after every 5 days, 5 more workers join the work. In how many days the work will be completed ?
(A) 20 (B) 25 (C) 30 (D) 35

Answer 1

• Given:- A work is expected to be completed by 20 workers in 25 days. The work is started by 10 workers. Then,

after every 5 days, 5 more workers join the work.

• To find:- how many days the work will be completed

• Solution:-

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

So, men were

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/(25×20) = 1/500 part of the job.

Now, let us assume that the total working days is x

So, as per the question, 10 men worked for 5 days and 15 men worked for (x-5) days.

So, to form an equation,

10×5/500 + 15(x-5)/500 = 1

=> 50/500+ (15x-75)/500=1

=> 15x = 525

=> x = 35

so, the work will be completed with in 35 days

Answer 2

Answer:

refer of image. hope this helps.