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 9 of 23.
Siva Ranjini said:
2 years ago
A = 48/16=3w/d
B = 48/12=4w/d
C = ?
Total work = 48.
One day completed work = 48/4 = 12.
3+4+? = 12.
C work per day = 5w/d.
C = 48/5.
Ans = 9 3/5 days.
B = 48/12=4w/d
C = ?
Total work = 48.
One day completed work = 48/4 = 12.
3+4+? = 12.
C work per day = 5w/d.
C = 48/5.
Ans = 9 3/5 days.
(96)
Shantanu said:
1 decade ago
Reema
look
A's 1 day's work = 1/16
because he took 16 days to complete the task
similarly
C's 1 day's work =5/48
so total no. of days will be 48/5
look
A's 1 day's work = 1/16
because he took 16 days to complete the task
similarly
C's 1 day's work =5/48
so total no. of days will be 48/5
Jagan said:
1 decade ago
@ Uthappa
1/4-7/48 = ((48*1)-(7*4))/(4*48) //cross multiplication
=(48-28)/192 = 20/192 //ok........ now its divisible by 4
=5/48 // r u got it?
1/4-7/48 = ((48*1)-(7*4))/(4*48) //cross multiplication
=(48-28)/192 = 20/192 //ok........ now its divisible by 4
=5/48 // r u got it?
Shivam sharma said:
8 years ago
Help here, let's take c's work to be X then (1/16 + 1/12 + 1/X) = 1 but when I find for X by multiplying 4 inside of the bracket. I get a 80/11.
Lijin said:
10 years ago
How it possible to write 5/48 to 48/5?
See A can complete a work in n days.
A's 1 day work = 1/n.
So here 1/n = 5/48.
So n = 48/5.
Got it!
See A can complete a work in n days.
A's 1 day work = 1/n.
So here 1/n = 5/48.
So n = 48/5.
Got it!
Jack said:
1 decade ago
B's 1 day's work = 1/12.
Therefore 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 = 93 days.
Therefore 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 = 93 days.
Sankalp said:
9 years ago
Hi, I have a doubt. Please clarify it.
After finding LCM why do we reverse the answer? (i.e why do we have 48/5 after getting LCM as 5/48).
After finding LCM why do we reverse the answer? (i.e why do we have 48/5 after getting LCM as 5/48).
Prachi said:
10 years ago
Like a b c are doing work in four days then can we assume the approach like it.
1/16 + 1/12+x = 4.
So x = 41/48, work of c.
Please tell.
1/16 + 1/12+x = 4.
So x = 41/48, work of c.
Please tell.
Sona said:
1 decade ago
Hey I understood they gave answer in fraction form so 5/48 we need not any fraction so its inverse 48/5.
C = 1/4 = 5/48.
C = 4 = 48/5.
C = 1/4 = 5/48.
C = 4 = 48/5.
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.
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