Aptitude - Time and Work - Discussion

Total work is 48 units.

A can do work in 16 days.

It means A completes 3 units per day.

B can do work in 12 days.

It means B completes 4 units per day.

Now A and B is helped by C and completed work in 4 days.

It means A, B and C together doing 12 units per day.

It means A+B+C = 12.

Sub A and B values.

3+4+C = 12.

C = 5.

It means C completes 5 units per day.

For 48 units?

Answer: 48/5.

Awesome answers the way of explaining is very excellent. Thank you all of you.

How it come 5/48? Please give a clear solution.

@Ganesh.

Thanks for explaining the answer.

Hi, I have a doubt. Please clarify it.

After finding LCM why do we reverse the answer? (i.e why do we have 48/5 after getting LCM as 5/48).

Thank you very much friends, I got lots of help because of yours discussion with this topic.

A can complete 1/16th of the work in 1 day.

B can complete 1/12th of the work in 1 day.

Let C complete 1/Xth of the work in 1 day.

So, A, B & C can complete (1/16 + 1/12 + 1/X)th part of the work in 1 day.

Therefore in 4 days, they together can complete = 4*(1/16 + 1/12 + 1/X)th part of the work . Always remember & denote work completed as 1.

On solving 4*(1/16 + 1/12 + 1/X) = 1, you can get the value of x which is the number of days taken by C to do the work.

Hope it helps you.

A's efficiency = 3, and B's efficiency =4, so (3 + 4) = 5 then C's efficiency (12 - 7) =5, So total work take LCM of (16, 12, 4) = 48, so C alone finished the work 48/5.

@Shantanu

Thank you, you are right.

Actually, A can solve in 16 days for one day it will be 1/16. if we take for 2 days work it will become 2/16. in the same way the work done by c per day is 5/48. If you want total work done by 'c' just reverse the fraction like 48/5.

Ex: THE TOTAL WORK DONE BY 'B' IS IN 12DAYS, FOR ONE DAY 12,IN THE SCENE 12/1. You should remember that 5/48 is the work done by 'c' in one day.

Thanks for clarifying the solution @Ajay.