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 1 of 23.
AMIT said:
1 decade ago
How the fractional 7/48 arrived?
(1)
Gurjit said:
1 decade ago
Why did you write 5/48 as 48/5 ?
Aparna said:
1 decade ago
@amit
First solve the bracket,
it is
(1/16+1/12)
First method:
Simply you can do cross multiplication
we get
(12+16)/12*16
after solving we get
7/48
Second method:
Find the lcm of denominators
that's of 12 and 16
It is 48,and multiply it with each fractions
i:e
we get
(3+4)/48
First solve the bracket,
it is
(1/16+1/12)
First method:
Simply you can do cross multiplication
we get
(12+16)/12*16
after solving we get
7/48
Second method:
Find the lcm of denominators
that's of 12 and 16
It is 48,and multiply it with each fractions
i:e
we get
(3+4)/48
Aparna said:
1 decade ago
@gurjit
as per formula,
If A's 1 day's work = 1/n , then A can finish the work in n days.
here also same
c's one days work=5/48
hence he can complete whole work in 48/5 days,tats asked to us
and remember any fraction can also be written in
quotient*remainder/divisor format
when solved 48/5
quotient=9
remainder=3
divisor=5
hence,
9*3/5
as per formula,
If A's 1 day's work = 1/n , then A can finish the work in n days.
here also same
c's one days work=5/48
hence he can complete whole work in 48/5 days,tats asked to us
and remember any fraction can also be written in
quotient*remainder/divisor format
when solved 48/5
quotient=9
remainder=3
divisor=5
hence,
9*3/5
Bharathi said:
1 decade ago
How should know A, B, C work is 1/4.
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
Sowjanya said:
1 decade ago
Thanks geeta you solved my doubt.
Reema said:
1 decade ago
How did 5/48 come explain it?
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.
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
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