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 5 of 15.
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.
Anchal said:
1 decade ago
Best method is Awoke method, because this is shortcut for doing in competative exams. But for understandin the solution, we can see Nagu's method.
So good job have done by both the guys. Thankyou.
So good job have done by both the guys. Thankyou.
Nagu said:
1 decade ago
Hi Guys, sorry for the late and here is the explanation about you doubt.
In my previous explanation I mentioned
(a+b+c)'s one day work = 3/25
and a+b+c = 2a here b+c=a means a's one day work = b+c's one day work
then a's one day work+(b+c)'s one day work = 3/25
so a+a = 3/25
2a = 3/25
so here 2* a's one days work = 3/25
So I think u can under stand now
keep practicing.....
In my previous explanation I mentioned
(a+b+c)'s one day work = 3/25
and a+b+c = 2a here b+c=a means a's one day work = b+c's one day work
then a's one day work+(b+c)'s one day work = 3/25
so a+a = 3/25
2a = 3/25
so here 2* a's one days work = 3/25
So I think u can under stand now
keep practicing.....
DHARMENDRA said:
1 decade ago
A=B+C-----------------(1)
A+B=1/10--------------(2)
C=1/50----------------(3)
(1)+(2)
(B+C)+B=1/10-----------(4)
(3)+(4)
B+(1/50)+B=1/10
2B=(1/10)-(1/50)
B=1/25
SO B COMPLETE THE TASK IN 25 DAYS
A+B=1/10--------------(2)
C=1/50----------------(3)
(1)+(2)
(B+C)+B=1/10-----------(4)
(3)+(4)
B+(1/50)+B=1/10
2B=(1/10)-(1/50)
B=1/25
SO B COMPLETE THE TASK IN 25 DAYS
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