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:
224 comments Page 11 of 23.
Vamsi said:
1 decade ago
LCM of numbers 16, 12, 4 = 48.
16 is 3 times.
12 is 4 times.
4 is 12 times.
a-16d-3 units.
b-12d-4 units.
c-?- ? units.
a+b+c = 12 units .
Total work complete 12 units.
a+b complete 7.
Remaining work c 5.
= total/remaining work, 48/5 = 9.6 this is also written 9 3/5.
16 is 3 times.
12 is 4 times.
4 is 12 times.
a-16d-3 units.
b-12d-4 units.
c-?- ? units.
a+b+c = 12 units .
Total work complete 12 units.
a+b complete 7.
Remaining work c 5.
= total/remaining work, 48/5 = 9.6 this is also written 9 3/5.
Arun kumar arui said:
1 decade ago
A+B+C = 1/4.
1/16+1/12+1/x = 1/4.
(1/16+1/12-1/4) = -1/x.
Taking lcm.
-5/48 = -1/x.
cross multiplying,
-5x = -48.
x = 48/5.
x = 9 3/5.
1/16+1/12+1/x = 1/4.
(1/16+1/12-1/4) = -1/x.
Taking lcm.
-5/48 = -1/x.
cross multiplying,
-5x = -48.
x = 48/5.
x = 9 3/5.
Des said:
1 decade ago
How did they get 48 in 7/48?
Raga said:
1 decade ago
Why 5/48 concert to 48/5 please clarify me?
Kaustav said:
1 decade ago
One step equation:1/16+1/12+1/x=1/4.
Amruta said:
1 decade ago
Amruta here,
Lets see this simple method,
Lcm of 16 and 12 is 48.
So A and B will finish their work in 3 and 4 hr.
Answer C will finish in 12 hr.
Hence 12- (3+4) = 5 hr.
Hence answer is 48/5.
Lets see this simple method,
Lcm of 16 and 12 is 48.
So A and B will finish their work in 3 and 4 hr.
Answer C will finish in 12 hr.
Hence 12- (3+4) = 5 hr.
Hence answer is 48/5.
Prachi said:
1 decade ago
Can you explain me why 5/48 reverse?
Aditya said:
1 decade ago
'A' work in 16 days.
Working of 'A' in one day is 1/16.
Similarly working of 'C' in one day is 5/48.
So 'C' work finished.
Working of 'A' in one day is 1/16.
Similarly working of 'C' in one day is 5/48.
So 'C' work finished.
Guri said:
1 decade ago
@Aparna.
LCM. Method is the best shortcut but expect common sense more than you have.
LCM. Method is the best shortcut but expect common sense more than you have.
Aaja said:
1 decade ago
Hi,
How to convert decimal to fraction?
How to convert decimal to fraction?
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