Aptitude - Time and Work - Discussion

Discussion Forum : Time and Work - General Questions (Q.No. 2)
2.
A can lay railway track between two given stations in 16 days and B can do the same job in 12 days. With help of C, they did the job in 4 days only. Then, C alone can do the job in:

9 1 days
5

9 2 days
5

9 3 days
5

10
Answer: Option
Explanation:

(A + B + C)'s 1 day's work = 1 ,
4

A's 1 day's work = 1 ,
16

B's 1 day's work = 1 .
12

Therefore C's 1 day's work = 1 - ( 1 + 1 ) = ( 1 - 7 ) = 5 .
4 16 12 4 48 48

So, C alone can do the work in 48 = 9 3 days.
5 5

Discussion:
224 comments Page 10 of 23.

Sudhanshu patra said:   9 years ago
@Ganesh.

Thanks for explaining the answer.

Sidhartha said:   9 years ago
How it come 5/48? Please give a clear solution.

Mathivanan said:   10 years ago
Awesome answers the way of explaining is very excellent. Thank you all of you.

Ganesh said:   10 years ago
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.
(1)

Prachi said:   10 years ago
Like a b c are doing work in four days then can we assume the approach like it.

1/16 + 1/12+x = 4.

So x = 41/48, work of c.

Please tell.

Kumar said:   10 years ago
@Amit.

It is addition.

Dikesh said:   10 years ago
Hi all,

If we convert 5/48 can lead to decimal, normally we won't measure days of decimal, hence we have to reverse it simple that's it. I think all you guys understood this.

Abhishek said:   10 years ago
A - 16 days | 3 unit/day

L. C. M of (16, 12, 4).

| | = 48.

B - 12 days |4 unit/day|.

| |.

C - ? |x unit/day|.

-------------------------------------------------.

(A+B+C) - 4 days | 12 unit/day |.

So, for C we get (12-3+4) = 5 unit/day.

If C can do 5 unit in 1 day, then 48 unit can be done in 48/5 = 9*3/5 days.

Guys this is the easiest way.

Onkar Vitthal Dabhole said:   10 years ago
A very very simple solution than the provided as above.

A can complete a work in 16 days, B can complete the same work in 12 days and with the help of C together if they complete the work in 4 days, so assume total work to be done is 48. (LCM of 16, 12, 4).

Persons A B C | A+B+C.

Days- 16 12x = (48/5) = (9+3/5)4.

Work/day- 3 4 5 12 = 3+4+C.

Hence C = 5.

----------------------------------------------------------------.

Work - 48 48 48 48.

Sagar said:   10 years ago
Anyone explain me what is 5 and 48 in relation to C?


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