Aptitude - Time and Work - Discussion
Discussion Forum : Time and Work - General Questions (Q.No. 26)
26.
A and B can do a work in 8 days, B and C can do the same work in 12 days. A, B and C together can finish it in 6 days. A and C together will do it in :
Answer: Option
Explanation:
| (A + B + C)'s 1 day's work = | 1 | ; |
| 6 |
| (A + B)'s 1 day's work = | 1 | ; |
| 8 |
| (B + C)'s 1 day's work = | 1 | . |
| 12 |
 (A + C)'s 1 day's work |
|
||||||||||||||
|
|||||||||||||||
|
|||||||||||||||
|
So, A and C together will do the work in 8 days.
Discussion:
53 comments Page 3 of 6.
Ricky nahar said:
7 years ago
@Nandhu.
Why a=2?
Why a=2?
Vishal sinha said:
6 years ago
It can be done in a much simpler way.
(A+B)'s 1-day work = 1/8.
(B+C)'s 1-day work = 1/12.
(A+B)+(B+C)'s 1 day work= 1/8+1/12.
B+(A+B+C)=5/24,
B=5/24-1/6,
B=1/24.
So, A+B+C=1/6,
Putting the value of B.
(A+C)'s 1 day work = 1/6 - 1/24 = 1/8.
Time taken = 8 days.
(A+B)'s 1-day work = 1/8.
(B+C)'s 1-day work = 1/12.
(A+B)+(B+C)'s 1 day work= 1/8+1/12.
B+(A+B+C)=5/24,
B=5/24-1/6,
B=1/24.
So, A+B+C=1/6,
Putting the value of B.
(A+C)'s 1 day work = 1/6 - 1/24 = 1/8.
Time taken = 8 days.
Rehan said:
6 years ago
(A+B)+(B+C)+(C+A) = 2 (A+B+C).
1/8 + 1/12+ (C+A) = 2 * 1/6.
1/8 + 1/12+ (C+A) = 2 * 1/6.
Bhanu said:
1 decade ago
(A + B + C)'s 1 day's work = 1/6
(A + B)'s 1 day's work = 1/8
(B + C)'s 1 day's work = 1/12
so c's 1 day's work=1/6-1/8=1/24
and a's 1 day's work=1/6-1/12=1/12
and b's 1 day work=1/6(1/24+1/12)=1/4
so a and c 1'day work=1/12+1/24=1/8
(A + B)'s 1 day's work = 1/8
(B + C)'s 1 day's work = 1/12
so c's 1 day's work=1/6-1/8=1/24
and a's 1 day's work=1/6-1/12=1/12
and b's 1 day work=1/6(1/24+1/12)=1/4
so a and c 1'day work=1/12+1/24=1/8
Anishkumar said:
1 decade ago
Assume A+C as x
so now
2(A+B+C)=1/8+1/12+1/x
2(1/6) =5/24+1/x
finally
x =8
so now
2(A+B+C)=1/8+1/12+1/x
2(1/6) =5/24+1/x
finally
x =8
Kavitha said:
1 decade ago
Why did you take 1/6 (1/12+1/24) ?
Gulshan said:
1 decade ago
24 is lcm of 8 & 12
Pandeswari Durai Pandi said:
5 years ago
@Nanthu.
Thank you for using LCM method it makes me to understand it easily.
Thank you for using LCM method it makes me to understand it easily.
Sabarimani said:
1 decade ago
Is b's 1day work=1/6-(1/24+1/12)?
Azuu said:
1 decade ago
How to take lcm of 1/8+1/12 ?
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers