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 23 of 36.
Subash said:
9 years ago
In 3 days they work is 1/5;
Then remaining work is 1 - 1/5 = 4/5,
So using proportions 1/5 : 45 :: 3 : x.
Get 12days.
+ 3days = 15days.
Then remaining work is 1 - 1/5 = 4/5,
So using proportions 1/5 : 45 :: 3 : x.
Get 12days.
+ 3days = 15days.
PARSHU said:
9 years ago
3 values there 3persons working to gather assisted A's B + C we calculate A + B + C/2 we get,
A+ B + C = 1/20 + 1/30 + 1/60.
LCM denomineor = 1/10 = 10 * 3 total 30/2 = 15-> 3persons work.
A+ B + C = 1/20 + 1/30 + 1/60.
LCM denomineor = 1/10 = 10 * 3 total 30/2 = 15-> 3persons work.
Sid said:
9 years ago
According to me, the answer is [1/10 + 1/10 + 1/20] = 1/4 for 3 days the whole days is 4 * 3 = 12.
Harsha said:
9 years ago
According to the question the A has been assisted by B and C after the third day.
It means the A has to work for three days and the third day is followed by B and C.
It means the A has to work for three days and the third day is followed by B and C.
Sarathy said:
9 years ago
A's total work = 1.
A's 1 day work = 1/20 = 0.05.
B's 1 day work = 1/30 = 0.03.
c's 1 day work = 1/60 = 0.01.
B + C combined work together = 0.03 + 0.01 = 0.04.
A's 3 day work = 0.05 + 0.05 + 0.05 + 0.04 = 0.19.
If answer is 15 means = 5 * (0.19) = 0.95 remaining 0.05.
So, the answer is wrong.
In 16th day = (15days work + A's one day work).
= (0.95 + 0.05),
= 1.
So, 16 days is the correct answer.
A's 1 day work = 1/20 = 0.05.
B's 1 day work = 1/30 = 0.03.
c's 1 day work = 1/60 = 0.01.
B + C combined work together = 0.03 + 0.01 = 0.04.
A's 3 day work = 0.05 + 0.05 + 0.05 + 0.04 = 0.19.
If answer is 15 means = 5 * (0.19) = 0.95 remaining 0.05.
So, the answer is wrong.
In 16th day = (15days work + A's one day work).
= (0.95 + 0.05),
= 1.
So, 16 days is the correct answer.
Puspanjalisahoo said:
9 years ago
I am not understanding A's 2 day's work. Please explain.
Priya said:
9 years ago
@All.
Please explain the last step.
Please explain the last step.
Rudra said:
9 years ago
Here, first of all, we have to find the total work.
So for this, L.C.M of 20 30 60 = 60,
a's b's c's one day work =3 2 1 (one day work)
Now a's 2days work = 6.
b's, c,s one day's woks = 2.
+1= 3.
So three days work 3 + 3 + 3 + 3 = 12.
3 days = 12
3*5 =15 days, 12 * 5 = 60.
So for this, L.C.M of 20 30 60 = 60,
a's b's c's one day work =3 2 1 (one day work)
Now a's 2days work = 6.
b's, c,s one day's woks = 2.
+1= 3.
So three days work 3 + 3 + 3 + 3 = 12.
3 days = 12
3*5 =15 days, 12 * 5 = 60.
Anand J said:
9 years ago
I'm finding difficulty in understanding the question. How to analyze the question? Please help me out.
Mohammed said:
9 years ago
Why here they take 2?
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