Question

if 5 men complete one third of a work then how many work will be sompleted by 7 man in the same time?​

Answer 1

Answer:

If 5 workers complete one task in 7 days, then how many days will 7 workers take to complete the same task?

Applying the concept of Man-Days (or Man-Hours) is the easiest for such problems -

5 workers complete the task in 7 days, so total task that needs to be done is

5*7 = 35 Man-Days..

So, if 7 workers need to complete the same task (i.e. 35 Man-Days) they'll take 5 days ( = 35/7) to complete it.

Alternatively, a different approach -

Calculate the amount of work done by 1 worker in 1 day and then find out the required answer...

5 workers work for 7 days.

So, in one day amount of task done by 5 workers = 1/7

in one day amount of task done by 1 worker = 1/35

Now, if 7 workers are working together, then on each day the amount of work done by them would be = (1/35) * 7 = 1/5

Time required to complete the entire work = 1/ (1/5) = 5 Days.