Aptitude - Time and Work - Discussion
Discussion Forum : Time and Work - General Questions (Q.No. 16)
16.
X and Y can do a piece of work in 20 days and 12 days respectively. X started the work alone and then after 4 days Y joined him till the completion of the work. How long did the work last?
Answer: Option
Explanation:
| Work done by X in 4 days = |  |
1 | x 4 |  |
= | 1 | . |
| 20 | 5 |
| Remaining work = | |
1 - | 1 | |
= | 4 | . |
| 5 | 5 |
| (X + Y)'s 1 day's work = | |
1 | + | 1 | |
= | 8 | = | 2 | . |
| 20 | 12 | 60 | 15 |
| Now, | 2 | work is done by X and Y in 1 day. |
| 15 |
| So, | 4 | work will be done by X and Y in | |
15 | x | 4 | |
= 6 days. |
| 5 | 2 | 5 |
Hence, total time taken = (6 + 4) days = 10 days.
Discussion:
68 comments Page 5 of 7.
Suraj said:
10 years ago
They said in question in a piece of so how it's possible whole work done by them.
Chandra said:
1 decade ago
Because 4 days work done by x. In question they asked total number of days.
Chandra said:
1 decade ago
Because 4 days work done by x. In question they asked total number of days.
Bhavesh said:
8 years ago
Can we do like this?
(4/20)+(x/12)=1.
It give 9.6 and dats means 10days.
(4/20)+(x/12)=1.
It give 9.6 and dats means 10days.
Tom Cruz said:
7 years ago
x/20 + (x-4)/12 = 1,
12x + 20x - 80 = 240,
32x = 320,
x = 10 days.
12x + 20x - 80 = 240,
32x = 320,
x = 10 days.
(2)
Vikas said:
2 decades ago
Ramchandra please explain it clearly. It is not understandable.
Mitra said:
1 decade ago
(x+4)/20 + x/12 = 1
solving x = 6 days
total days 4+6=10days
solving x = 6 days
total days 4+6=10days
Prudhvi said:
8 years ago
(4/20)+x(1/20+1/12) = 1,
Solve for x.
x=6.
Total days = x+4.
Solve for x.
x=6.
Total days = x+4.
Patel Komal said:
9 years ago
Please help me to get this, why you take (1/20 * 4)?
Ved Prakash Singh said:
8 years ago
4/20+x/20+x/12=1.
X=6 so total days=6+4=10days.
X=6 so total days=6+4=10days.
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