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.
Monu Monika said:
8 years ago
Work is inversely proportional to days 5/48 is the answer for work To convert it into days he changed 5/48 into 48/5.
Yogesh sayam said:
1 decade ago
5/48 calculation is:
1/4-7/48 is cross multiplication.
28-48/192 = 20/192 (divided by 2) .
= 10/96 Answer is 5/48.
1/4-7/48 is cross multiplication.
28-48/192 = 20/192 (divided by 2) .
= 10/96 Answer is 5/48.
Anup said:
6 years ago
16,12,4 of lcm=48.
16/48=3.
12/28=4.
4/48=12.
So, total works efficiency =12-7=5 per days;
48/5 is the answer.
16/48=3.
12/28=4.
4/48=12.
So, total works efficiency =12-7=5 per days;
48/5 is the answer.
Justine said:
7 years ago
How come that 48 gets retain? when you cross multiply 48/1 * 1/16 = 3 and 48/1 * 1/12 = 4?
Please explain me.
Please explain me.
Naresh kumar said:
1 decade ago
Thanks Aparna and Geetha. You have solved my doubt also.
I am very poor in solving such types of question.
I am very poor in solving such types of question.
Geetha said:
1 decade ago
@Bharathi
In ques they have mentioned that
with the help of C they did the job in 4 days
thatsy A+B+C=1/4
In ques they have mentioned that
with the help of C they did the job in 4 days
thatsy A+B+C=1/4
RAMAKRISHNA MACHARLA said:
2 years ago
A = 1/16.
B = 1/12.
A+B+C = 1/4.
1/16 + 1/12 + C = 1/4
C = 1/4 - 1/16 - 1/12
C = 5/48 = 48/5.
C = 9 * 3/5.
B = 1/12.
A+B+C = 1/4.
1/16 + 1/12 + C = 1/4
C = 1/4 - 1/16 - 1/12
C = 5/48 = 48/5.
C = 9 * 3/5.
(99)
Manoj Kumar said:
1 decade ago
Why you have shown in the last fraction 48/5 in where the result has come out 5/48? Please explain it.
Tiny said:
1 decade ago
@chandrakant.
Your method is totaly wrong. When c comes in right hand side it will become negative.
Your method is totaly wrong. When c comes in right hand side it will become negative.
Udita said:
1 decade ago
@Saquib Ali.
Please explain the following step.
Units of work in a day by a = 48x/16 = 48 units.
Please explain the following step.
Units of work in a day by a = 48x/16 = 48 units.
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