Aptitude - Pipes and Cistern - Discussion
Discussion Forum : Pipes and Cistern - General Questions (Q.No. 8)
8.
Two pipes A and B together can fill a cistern in 4 hours. Had they been opened separately, then B would have taken 6 hours more than A to fill the cistern. How much time will be taken by A to fill the cistern separately?
Answer: Option
Explanation:
Let the cistern be filled by pipe A alone in x hours.
Then, pipe B will fill it in (x + 6) hours.
 |
1 | + | 1 | = | 1 |
| x | (x + 6) | 4 |
 |
x + 6 + x | = | 1 |
| x(x + 6) | 4 |
x2 - 2x - 24 = 0
(x -6)(x + 4) = 0
x = 6. [neglecting the negative value of x]
Discussion:
18 comments Page 2 of 2.
Shivam said:
1 decade ago
4(2x+6) = x2+6x
0=-24-2x+x2
x2-2x-24 = 0
(x-6)(x+4) = 0
x=6 or x =-4
0=-24-2x+x2
x2-2x-24 = 0
(x-6)(x+4) = 0
x=6 or x =-4
(1)
Priya said:
8 years ago
How (x+6) will come?
(x-6) only will come.
(x-6) only will come.
Ajay said:
8 years ago
How x2-2x-24= (x-6) (x+4)? Please explain.
Aman said:
1 decade ago
Why we reciprocal the equation?
Kishan said:
9 years ago
Good explanation @Rashmibs.
Nirmala Devi said:
9 years ago
How x + 6? Explain.
Neha said:
9 years ago
Please explain it.
Sakib said:
7 years ago
Please explain.
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