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 4 of 35.
Ankita said:
4 years ago
@Jyoti.
It's 1 -7/15 as it is asking how much work is left. Which means 1 is the total amount of work, and 7/15 is the amount of work completed.
So, to get the remaining work we hv to subtract the work done by the whole work. Which is
1-7/15.
= 15/15 - 7/15.
= 15-7/15.
= 8/15.
Hope it helps.
It's 1 -7/15 as it is asking how much work is left. Which means 1 is the total amount of work, and 7/15 is the amount of work completed.
So, to get the remaining work we hv to subtract the work done by the whole work. Which is
1-7/15.
= 15/15 - 7/15.
= 15-7/15.
= 8/15.
Hope it helps.
(15)
Ashim said:
1 year ago
How 7/60 came? Anyone, please explain to me.
(14)
Hari said:
11 months ago
@Vishnu.
Can you explain the process in detail please?
Can you explain the process in detail please?
(14)
VisHnu RaM said:
3 years ago
Thank you for giving the clear explanation @Swetha.
And 60 will come, No of days LCM
15 days to 15 * 4 = 60.
20 days to 20 * 3 = 60.
So, the LCM is 60.
And 60 will come, No of days LCM
15 days to 15 * 4 = 60.
20 days to 20 * 3 = 60.
So, the LCM is 60.
(13)
UMAKANT CHAUDHARY said:
1 month ago
To solve this type of question,if days are given and if we have to find together work finishing days then,
= (15+20)/15 * 20,
= 35/300,
= 7/60.
Now, in 4 days they can do 4 * 7/60,
= 7/15.
So, Remaining work = 1-(7/15).
= 8/15.
= (15+20)/15 * 20,
= 35/300,
= 7/60.
Now, in 4 days they can do 4 * 7/60,
= 7/15.
So, Remaining work = 1-(7/15).
= 8/15.
(12)
Mish said:
2 years ago
@All.
Why (A+B)'s 4 days of work is calculated?
Why it's not 3,5,6,7 or any other day?
What is the logic behind it?
Why (A+B)'s 4 days of work is calculated?
Why it's not 3,5,6,7 or any other day?
What is the logic behind it?
(10)
Syam said:
6 months ago
@Sree.
15 is written as = 5 * 3 and 20 is written as 2^2 *5 then 5 is the common then from 15 take 3 and 20 take 2 square, then 4*3*5=60 then 1 * 4/15 * 4 = 4/60 and for 1/20 =1 * 3/20 * 3 = 3/60.
Then the final answer is 4/60 + 3/60 = 7/60.
15 is written as = 5 * 3 and 20 is written as 2^2 *5 then 5 is the common then from 15 take 3 and 20 take 2 square, then 4*3*5=60 then 1 * 4/15 * 4 = 4/60 and for 1/20 =1 * 3/20 * 3 = 3/60.
Then the final answer is 4/60 + 3/60 = 7/60.
(10)
Kalai said:
1 year ago
How remaining work =1? Please explain to me.
(7)
Sugan said:
1 year ago
1 (total work) - 7/15 (together completed work in 4 days).
Lcm = 15 then (15/15 -7/15) = 8/15.
Lcm = 15 then (15/15 -7/15) = 8/15.
(7)
Swetha said:
3 years ago
First of all, thank you to explain the method.
I have a doubt that how we know to take (i.e Total work = 60)?
Anyone, please help me to get it.
I have a doubt that how we know to take (i.e Total work = 60)?
Anyone, please help me to get it.
(6)
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