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:
347 comments Page 28 of 35.
Ramkali said:
9 years ago
Why do we want to calculate 1-7/15?
Sunita Devi said:
9 years ago
Why this answer is not sufficient at this term : (7/15)?
Why do this term (1-8/15)?
Why do this term (1-8/15)?
Ammu said:
9 years ago
A's 1 day work = 1/15.
B's 1 day work = 1/20.
Together for 1 day=(1/15+1/20),
=(4+3)/60,
=7/60.
together for 4 days=(7/60) * 4,
= 7/15.
If total work is 1.
Then the rest is = 1 - 7/15,
= 8/15.
B's 1 day work = 1/20.
Together for 1 day=(1/15+1/20),
=(4+3)/60,
=7/60.
together for 4 days=(7/60) * 4,
= 7/15.
If total work is 1.
Then the rest is = 1 - 7/15,
= 8/15.
Santhosh said:
9 years ago
Can anyone explain this in LCM method?
Prashant Devada said:
9 years ago
@Akash.
You are great, LCM concept makes easy to understand.
Thanks.
You are great, LCM concept makes easy to understand.
Thanks.
Praveen behera said:
9 years ago
Why (1- 7/15) is applied as 8/15?
Can anybody explain it please?
Can anybody explain it please?
Juhi saxena said:
9 years ago
If both 1 day work is 7 then 4 days work is 28 and remaining is 32 how can I change it into fraction? Please explain.
Dhanalakshmi said:
9 years ago
Thanks for your explanation @Swetha.
Shubham said:
9 years ago
Thanks for the explanation @Swetha.
SUNDARA said:
9 years ago
A & B together requires 1/15+1/20=7/60 or 60/7days =8 4/7 days to complete the work.
After 4 days work, pending work is 8 4/7 -4=4 4/7days work.
= 4 4/7 divide by 8 4/7=32/7 divide 60/7=32/60=8/15 work pending.
After 4 days work, pending work is 8 4/7 -4=4 4/7days work.
= 4 4/7 divide by 8 4/7=32/7 divide 60/7=32/60=8/15 work pending.
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers