Aptitude - Time and Work - Discussion
Discussion Forum : Time and Work - General Questions (Q.No. 28)
28.
X can do a piece of work in 40 days. He works at it for 8 days and then Y finished it in 16 days. How long will they together take to complete the work?
Answer: Option
Explanation:
| Work done by X in 8 days = |  |
1 | x 8 |  |
= | 1 | . |
| 40 | 5 |
| Remaining work = | |
1 - | 1 | |
= | 4 | . |
| 5 | 5 |
| Now, | 4 | work is done by Y in 16 days. |
| 5 |
| Whole work will be done by Y in | |
16 x | 5 | |
= 20 days. |
| 4 |
 X's 1 day's work = |
1 | , Y's 1 day's work = | 1 | . |
| 40 | 20 |
| (X + Y)'s 1 day's work = | |
1 | + | 1 | |
= | 3 | . |
| 40 | 20 | 40 |
| Hence, X and Y will together complete the work in | |
40 | |
= 13 | 1 | days. |
| 3 | 3 |
Discussion:
33 comments Page 2 of 4.
Thiru said:
5 years ago
Take X's work as 1/40 he can do the work in only 8 days so 1/40*8=1/5.
Now 4/5 part of the work is remaining so Y is completing 4/5 part in 16 days 4/5 * 16 = 1/20.
Asking whole men's work1/20+1/40 = 13 1/3 days.
Now 4/5 part of the work is remaining so Y is completing 4/5 part in 16 days 4/5 * 16 = 1/20.
Asking whole men's work1/20+1/40 = 13 1/3 days.
(1)
Irshad said:
1 decade ago
Let x can do 1 work in a hour. Then he will do 8 work in 8 hour.
Remaining work = 40-8 = 32.
32/y=16;
y=2.
Means y do 1 work in 2hours.
x+y=3.
Together they will do in 40/3 day.
Remaining work = 40-8 = 32.
32/y=16;
y=2.
Means y do 1 work in 2hours.
x+y=3.
Together they will do in 40/3 day.
Mohit said:
9 years ago
First LCM of 40 is 40,
x can work 40 days,
work = 1 unit,
8*1 = 8,
remaining work 40 - 8 = 32,
Y finished it in 16 days then = 32/16 = 2,
x+y = 1+2 = 3,
40/3 answer.
x can work 40 days,
work = 1 unit,
8*1 = 8,
remaining work 40 - 8 = 32,
Y finished it in 16 days then = 32/16 = 2,
x+y = 1+2 = 3,
40/3 answer.
(7)
Miftah said:
1 decade ago
The main reason for 16*5/4 is unitary method. It goes like this:
It takes 4/5 work to completed by C = 16 days.
So for 1 work it will take: 16*5/4.
It takes 4/5 work to completed by C = 16 days.
So for 1 work it will take: 16*5/4.
NARAYAN SAHOO said:
1 decade ago
x=40-8=32 ratio 2 capacity 1
y=16 ratio 1 capacity 2
Together done ration 3
Work is 40
Then 40/3
13.1/3
y=16 ratio 1 capacity 2
Together done ration 3
Work is 40
Then 40/3
13.1/3
Scarlett said:
10 years ago
I still can't get the 4/5 converted to 5/4. In some of the previous sums it was not converted then why here?
Sravani said:
1 decade ago
Ya we can't get. The remaining work of y is 4/5. But it taken has 5/4.
Yeezuu said:
5 years ago
I am not getting the answer, Can anybody help? please.
(3)
Student said:
1 decade ago
Can't get it because what does it mean of 16*5/4?
P.muthukumar said:
9 years ago
What is the reason for converting 4/5 to 5/4?
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