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:
351 comments Page 33 of 36.
Sak said:
1 decade ago
1/15 * 4/4 = 4/60 ok.
1/20 * 3/3 = 3/60 ok.
How do we get 4/4 and 3/3 ? Please explain.
1/20 * 3/3 = 3/60 ok.
How do we get 4/4 and 3/3 ? Please explain.
Depl said:
1 decade ago
Oh! Thanks I understood well.
Crompton said:
1 decade ago
Because we know that total work = 1 so we subtract with one.
Suba said:
1 decade ago
Why we subtract with one? can you please explain.
Vikas said:
1 decade ago
Thanks for your explanation. But it take much time. Can you tell me tricks.
Anshuman said:
1 decade ago
Oh! Thanks I understood well.
Latha said:
1 decade ago
Why the rest part is only 1-7/15 ?
Trupti said:
1 decade ago
Thanks Parthiban. I understood well.
Parthiban said:
1 decade ago
@Trupti
1-7/15 = (15-7)/15 = 8/15
I hope this will help you !
1-7/15 = (15-7)/15 = 8/15
I hope this will help you !
Trupti said:
1 decade ago
1-7/15 should be 6/15 please explaine how 8/15......
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