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:
344 comments Page 34 of 35.
Lottie said:
1 decade ago
I was thinking 1-7/15 will be 6/15. So how did you get 8/15. Thanx.
Malli said:
1 decade ago
@Prkash.
Superb explaination.
Superb explaination.
Well wisher said:
1 decade ago
@Poorni:
Why 1-(7/15)?
We consider the total work as 1.
The amount of (work done) is 7/15.
Subtract the total work by the work done we will get the amount of work to be done
That is why we use 1-(7/15).
Hope this help you.
Why 1-(7/15)?
We consider the total work as 1.
The amount of (work done) is 7/15.
Subtract the total work by the work done we will get the amount of work to be done
That is why we use 1-(7/15).
Hope this help you.
Vishwanath said:
1 decade ago
7/60 x4 =7/15 please explain me
PRAKASH said:
1 decade ago
For A:-
15 days for 1 job
in 1 day 1/15 (part of the one job)
for B:-
20 days for 1 job
in 1 day 1/20 (part of the one job)
FOR BOTH IN ONE DAY:-
1/15+1/20=7/60
FOR BOTH IN 4 DAYS:-
(7/60)*4=7/15(THEY HAVE DONE)
THE REST PART OF THE JOB IS:-
1-(7/15)=8/15 (ANS)
15 days for 1 job
in 1 day 1/15 (part of the one job)
for B:-
20 days for 1 job
in 1 day 1/20 (part of the one job)
FOR BOTH IN ONE DAY:-
1/15+1/20=7/60
FOR BOTH IN 4 DAYS:-
(7/60)*4=7/15(THEY HAVE DONE)
THE REST PART OF THE JOB IS:-
1-(7/15)=8/15 (ANS)
(1)
Sunny guleria said:
1 decade 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.
Pravin Hambire said:
1 decade ago
Can you explain how 7/60 came?
Mohideen said:
1 decade ago
@sundar.
Good explanation.
Good explanation.
Sundar said:
1 decade ago
@Beer Ibrahim
Q: Why (1-7/15) is applied ?
Ans: To calculate the work remaining. Work remaining = 8/15.
Note: From the above answer, we can say 15/8 days required to
complete the remaining work by A and B.
Hope this will help you. Have nice day!
Q: Why (1-7/15) is applied ?
Ans: To calculate the work remaining. Work remaining = 8/15.
Note: From the above answer, we can say 15/8 days required to
complete the remaining work by A and B.
Hope this will help you. Have nice day!
(1)
Beer ibrahim said:
1 decade ago
Why (1-7/15) is applied ?
(1)
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