Aptitude - Time and Work - Discussion
Discussion Forum : Time and Work - General Questions (Q.No. 1)
1.
A can do a work in 15 days and B in 20 days. If they work on it together for 4 days, then the fraction of the work that is left is :
Answer: Option
Explanation:
| A's 1 day's work = | 1 | ; |
| 15 |
| B's 1 day's work = | 1 | ; |
| 20 |
| (A + B)'s 1 day's work = |  |
1 | + | 1 |  |
= | 7 | . |
| 15 | 20 | 60 |
| (A + B)'s 4 day's work = | |
7 | x 4 | |
= | 7 | . |
| 60 | 15 |
| Therefore, Remaining work = | |
1 - | 7 | |
= | 8 | . |
| 15 | 15 |
Discussion:
355 comments Page 14 of 36.
RPV said:
1 decade ago
Why in this sum answer is not reciprocated in time and work problem the answer must be in reciprocal? Ex. 8/15 is written as 15/8 am correct.
RPV said:
1 decade ago
Tulsi and Ram can do a job alone in 20 days and 30 days respectively. In how many days the job will be finished if they work together?
Jansi said:
1 decade ago
I understood upto 7/15. I can't understand how they are telling total work 1. From that they were minusing 7/15 can you explain me.
Aravind_appu said:
1 decade ago
A = 1/15.
B = 1/20.
Together TH = A+B.
TH = (1/15+1/20).
TH/4 = (1/15+1/20).
TH = 4((35/15*20)).
TH = 7/15.
= 1-7/15 = 8/15.
B = 1/20.
Together TH = A+B.
TH = (1/15+1/20).
TH/4 = (1/15+1/20).
TH = 4((35/15*20)).
TH = 7/15.
= 1-7/15 = 8/15.
ASHLYMOL SAJU said:
1 decade ago
A B A+B.
15 20 4.
Work = Efficiency/Time.
Work = LCM of A B A+B.
W = 60.
A B A+B = 4 3 15.
Total = 7/15.
Remaining = 8/15.
15 20 4.
Work = Efficiency/Time.
Work = LCM of A B A+B.
W = 60.
A B A+B = 4 3 15.
Total = 7/15.
Remaining = 8/15.
Swetha said:
1 decade ago
@Sri harsha.p
It is not very long process..it is short method only.i explained every steps.,so only it looks like long process.
It is not very long process..it is short method only.i explained every steps.,so only it looks like long process.
Sunny guleria said:
2 decades ago
We have to calculate the remaining work after 4 dayz ,so why we subtract 1 dayz work from 4 day work? plz clear the question.
Shrikant said:
1 decade ago
a/b + c/d.
= a*d/b*d + c*b/b*d.
= ad+cb/b*d.
Maths rule if denominator not equal if equal directly cross multiplication.
= a*d/b*d + c*b/b*d.
= ad+cb/b*d.
Maths rule if denominator not equal if equal directly cross multiplication.
Shiva said:
1 decade ago
@Kiran.
(1/15+1/20) = (20+15)/300 //This get by cross multiplication.
= 35/300.
= 7/60.
I think your doubt is clear now.
(1/15+1/20) = (20+15)/300 //This get by cross multiplication.
= 35/300.
= 7/60.
I think your doubt is clear now.
Appu said:
2 decades ago
@Deepa
(1/50+1/20) = (20+15)/300 //This get by cross multiplication.
= 35/300
= 7/60.
I think your doubt is clear now.
(1/50+1/20) = (20+15)/300 //This get by cross multiplication.
= 35/300
= 7/60.
I think your doubt is clear now.
(1)
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