Aptitude - Time and Work - Discussion
Discussion Forum : Time and Work - General Questions (Q.No. 3)
3.
A, B and C can do a piece of work in 20, 30 and 60 days respectively. In how many days can A do the work if he is assisted by B and C on every third day?
Answer: Option
Explanation:
| A's 2 day's work = |  |
1 | x 2 |  |
= | 1 | . |
| 20 | 10 |
| (A + B + C)'s 1 day's work = | |
1 | + | 1 | + | 1 | |
= | 6 | = | 1 | . |
| 20 | 30 | 60 | 60 | 10 |
| Work done in 3 days = | |
1 | + | 1 | |
= | 1 | . |
| 10 | 10 | 5 |
| Now, | 1 | work is done in 3 days. |
| 5 |
Whole work will be done in (3 x 5) = 15 days.
Discussion:
357 comments Page 1 of 36.
Chirag Lakhani said:
2 decades ago
How step 3 is make 1/10+1/10? please explain it.
Vinoth said:
2 decades ago
How do you know total working day is 3 (last step).
(1)
Satyendra Sharma said:
2 decades ago
3 days work = 1/5
it means 1 day work =1/15
that is 1/15 work is done in 1 Day
now 4/5 part of work that is (1-1/5) will be done in :15*4/5 =12 days....
Hence total work done will done in (12 + 3 ) days...
it means 1 day work =1/15
that is 1/15 work is done in 1 Day
now 4/5 part of work that is (1-1/5) will be done in :15*4/5 =12 days....
Hence total work done will done in (12 + 3 ) days...
(1)
Abhishek said:
1 decade ago
@chirag:
Step 3 gives work done in first 3 day i.e. work done in 1st day + work done in 2nd day +work done in 3rd day = 1/20 (by A alone) + 1/20 (by B alone) + 1/10 (done by A, B and C together)
Similarly they continue and as per the question on every 3rd day A is joined by B and C.
Step 3 gives work done in first 3 day i.e. work done in 1st day + work done in 2nd day +work done in 3rd day = 1/20 (by A alone) + 1/20 (by B alone) + 1/10 (done by A, B and C together)
Similarly they continue and as per the question on every 3rd day A is joined by B and C.
Nitesh Nandwana said:
1 decade ago
Hi chirag don't go on step, here our aim is to compute total work done in 3 days once, first 2 days A is working alone and last 3rd day we are adding work's of B and C.
Sushant said:
1 decade ago
(A + B + C)'s 1 day's work = 1 + 1 + 1 = 6 = 1 .
20 30 60 60 10
how did we get 60
20 30 60 60 10
how did we get 60
Bala said:
1 decade ago
I can't get this.
Vikas said:
1 decade ago
Answer Explained:
A is working alone for two days, 3rd day he is assisted by B and C.
A's 1 day work=1/20
A working on 2 days=2*1/20=1/10
A+B+C working on 3rd day, so 1 day of working together=1/20+1/30+1/60=6/60=1/10
So total work done till 3rd day=1/10+1/10=2/10=1/5
So if in 3 days = 1/5 of work is completed....
Than, 3*5 days = 1/5*5 work will be completed.
=15days
A is working alone for two days, 3rd day he is assisted by B and C.
A's 1 day work=1/20
A working on 2 days=2*1/20=1/10
A+B+C working on 3rd day, so 1 day of working together=1/20+1/30+1/60=6/60=1/10
So total work done till 3rd day=1/10+1/10=2/10=1/5
So if in 3 days = 1/5 of work is completed....
Than, 3*5 days = 1/5*5 work will be completed.
=15days
(4)
Dhanam said:
1 decade ago
Why are you taking 2 days for first step?
Vishnu said:
1 decade ago
Why you have taken the a+b+c? A is assisted by only B, C know.
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