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:
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 |
 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:
228 comments Page 21 of 23.
Saquib Ali said:
2 decades ago
You can solve all these sums very fast...
a can do the work in 16 days
b can do the work in 12 days
c can do the work in x days
Calc LCM of 16, 12 and x = 48x
units of work in a day by a = 48x/16 = 3x units
units of work in a day by b = 48x/12 = 4x units
units of work in a day by a = 48x/16 = 48 units
Total units of work in a day = 3x + 4x + 48= 7x+48
Thus in 4 days = 4(7x+48)= 28x+192
Total units of work=48x
Thus,
28x+192=48x
20x=192
x=9 3/5 days.
a can do the work in 16 days
b can do the work in 12 days
c can do the work in x days
Calc LCM of 16, 12 and x = 48x
units of work in a day by a = 48x/16 = 3x units
units of work in a day by b = 48x/12 = 4x units
units of work in a day by a = 48x/16 = 48 units
Total units of work in a day = 3x + 4x + 48= 7x+48
Thus in 4 days = 4(7x+48)= 28x+192
Total units of work=48x
Thus,
28x+192=48x
20x=192
x=9 3/5 days.
Ravi said:
2 decades ago
Thanks uththapa. I get it.
Sowmya said:
2 decades ago
@Srikanth
9*3/5=(9*5)+3=48/5
9*3/5=(9*5)+3=48/5
Srikanth said:
2 decades ago
How 48/5 is written as 9*3/5 ?
Shimpi said:
2 decades ago
Please help me in 1/4-7/48.
Karthick said:
2 decades ago
Why the fraction 5/48 is changed to 48/5?
Sunaina said:
2 decades ago
Why we should take 16 and 12 as 1/16 and 1/12?
Sunil said:
2 decades ago
Why 48/5 is written? please help me.
Nikita said:
2 decades ago
1/4= 1/12+1/16+1/c
1/4-7/48=1/c
c=9*3/5
1/c= c's one day work
1/4-7/48=1/c
c=9*3/5
1/c= c's one day work
Mallik said:
2 decades ago
Reema explained clearly.
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