Aptitude - Time and Work - Discussion
Discussion Forum : Time and Work - General Questions (Q.No. 8)
8.
A can do a certain work in the same time in which B and C together can do it. If A and B together could do it in 10 days and C alone in 50 days, then B alone could do it in:
Answer: Option
Explanation:
| (A + B)'s 1 day's work = | 1 |
| 10 |
| C's 1 day's work = | 1 |
| 50 |
| (A + B + C)'s 1 day's work = |  |
1 | + | 1 |  |
= | 6 | = | 3 | . .... (i) |
| 10 | 50 | 50 | 25 |
A's 1 day's work = (B + C)'s 1 day's work .... (ii)
| From (i) and (ii), we get: 2 x (A's 1 day's work) = | 3 |
| 25 |
 A's 1 day's work = |
3 | . |
| 50 |
 B's 1 day's work |
|
1 | - | 3 | |
= | 2 | = | 1 | . |
| 10 | 50 | 50 | 25 |
So, B alone could do the work in 25 days.
Discussion:
146 comments Page 2 of 15.
Nishant said:
1 decade ago
LET B+C CAN FINISH WORK IN T DAYS
THEN B+C'S 1 day work=1/T.
then,
A's 1 day work=1/T.
so,
B+C's 1 day work=1/T.
now,(A + B)'s 1 day's work =1/10.
then B's 1 day work=1/10-1/T.--------(1)
and C's 1 day's work =1/50.
hence,B's 1 day work=i/T-1/50.-------(2)
now,
from (1) nd (2)
T = 25 days.
then B=50 days.
how it is possible????
THEN B+C'S 1 day work=1/T.
then,
A's 1 day work=1/T.
so,
B+C's 1 day work=1/T.
now,(A + B)'s 1 day's work =1/10.
then B's 1 day work=1/10-1/T.--------(1)
and C's 1 day's work =1/50.
hence,B's 1 day work=i/T-1/50.-------(2)
now,
from (1) nd (2)
T = 25 days.
then B=50 days.
how it is possible????
Aunjani Kumar said:
1 decade ago
From (i) and (ii), we get: 2 x (A's 1 day's work) = 3/25
Dear i am not able to understand why 2 multiplied with A's day's work??????
Dear i am not able to understand why 2 multiplied with A's day's work??????
Hilal said:
1 decade ago
B's work=x
C's work=y
hence A's work=x+y
A and B together work= 2x+y
given y=1/50
substituting x=1/25
C's work=y
hence A's work=x+y
A and B together work= 2x+y
given y=1/50
substituting x=1/25
Jay said:
1 decade ago
@sneha.
Your explanation is so simple, thanks a lot.
Your explanation is so simple, thanks a lot.
Ankit said:
1 decade ago
@Awoke
You are the best.
You are the best.
Sun said:
1 decade ago
A+b=10..2
c=1/50
sub (1) in (2)
2b+c=1/10
2b+1/50=1/10
2b=1/10-1/50
2b=5-1/50
2b=4/50
2b=2/25
b=25...
Hence proved
c=1/50
sub (1) in (2)
2b+c=1/10
2b+1/50=1/10
2b=1/10-1/50
2b=5-1/50
2b=4/50
2b=2/25
b=25...
Hence proved
Sumedha said:
1 decade ago
@Awoke.
Your short cut method is great.
Your short cut method is great.
Rajni Saini said:
1 decade ago
Awoke u r grreaatt dear.thnx a lot.
Logunath said:
1 decade ago
We have....
A+B=1/10......(2)
A=B+C,
C=1/50,
We can set,
A-B=C
A-B=1/50......(1)
solving 1 and 2...
A=3/50,
so B=1/25,
B can do it in 25 day's.
A+B=1/10......(2)
A=B+C,
C=1/50,
We can set,
A-B=C
A-B=1/50......(1)
solving 1 and 2...
A=3/50,
so B=1/25,
B can do it in 25 day's.
Pratiksha said:
1 decade ago
Thanku sneha I getting your explanation.
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers