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 21 of 35.
Krishna said:
9 years ago
I'm confused with this step (1 - 7/15). Can anyone explain this?
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 !
Merlin said:
1 decade ago
Can you just explain why they are subtracting the answer from 1?
Deepa said:
9 years ago
I'm confused with this stem (1 - 7/15). Can anyone explain this?
Kumar said:
1 decade ago
Why are we subtracting 7/15 from 1 ?
Why not any other number?
Why not any other number?
Dnyaneshwar said:
10 years ago
1*15 = 15.
15-8 = 7.
So that denominator remains same 7/15.
15-8 = 7.
So that denominator remains same 7/15.
Joni said:
9 years ago
Elaborate how you do this (1/50+1/20) where did you get 1/50?
Timilsina said:
6 years ago
A=1/15 and b=1/20 ,a+b=7/60*4 =7/15 so,
1-7/15 = 8/15.
1-7/15 = 8/15.
Crompton said:
1 decade ago
Because we know that total work = 1 so we subtract with one.
Miru said:
7 years ago
1-{4(1/15+1/20)}
=1-{4*7/60}
=1-1/15
8/15 is the answer (d).
=1-{4*7/60}
=1-1/15
8/15 is the answer (d).
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