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 35 of 35.
Anjali thakur said:
3 months ago
The answer is 8/15.
Lcm of 15 and 20.
Then it will give you 60.
Now 60/15 = 4, 60/20 = 3.
Together for one day 4 + 3=7.
For 4 days = 4 * 7=28.
60-28 = 32.
32/60 = 8/15.
Lcm of 15 and 20.
Then it will give you 60.
Now 60/15 = 4, 60/20 = 3.
Together for one day 4 + 3=7.
For 4 days = 4 * 7=28.
60-28 = 32.
32/60 = 8/15.
(49)
SFG said:
2 months ago
Thanks for explaining the answer @Anjali thakur.
(6)
Pankaj Kushwah said:
1 month ago
The answer is 8/15.
Lcm of 15 and 20.
Then it will give you 60.
Now 60/15 = 4, 60/20 = 3.
Together for one day 4 + 3 = 7.
For 4 days = 4 * 7 = 28.
60 - 28 = 32.
32/60 = 8/15.
Lcm of 15 and 20.
Then it will give you 60.
Now 60/15 = 4, 60/20 = 3.
Together for one day 4 + 3 = 7.
For 4 days = 4 * 7 = 28.
60 - 28 = 32.
32/60 = 8/15.
(48)
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)
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