Aptitude - Pipes and Cistern - Discussion
Discussion Forum : Pipes and Cistern - General Questions (Q.No. 1)
1.
Three pipes A, B and C can fill a tank from empty to full in 30 minutes, 20 minutes, and 10 minutes respectively. When the tank is empty, all the three pipes are opened. A, B and C discharge chemical solutions P,Q and R respectively. What is the proportion of the solution R in the liquid in the tank after 3 minutes?
Answer: Option
Explanation:
| Part filled by (A + B + C) in 3 minutes = 3 |  |
1 | + | 1 | + | 1 |  |
= | |
3 x | 11 | |
= | 11 | . |
| 30 | 20 | 10 | 60 | 20 |
| Part filled by C in 3 minutes = | 3 | . |
| 10 |
 Required ratio = |
|
3 | x | 20 | |
= | 6 | . |
| 10 | 11 | 11 |
Discussion:
75 comments Page 6 of 8.
Bibhuti Bhusan Swain said:
7 years ago
@Lalli.
When 1/30+1/20+1/10 add up they give 11/60.
When 1/30+1/20+1/10 add up they give 11/60.
Divya.chippada said:
7 years ago
Part filled by A in one min is given by=1/30 min.
Part filled by B in one min is given by=1/20 min.
Part filled by C in one min is given by=1/10 min.
Now, total (A+B+C)filled in 1 min is given as (1/30+1/20+1/10) by taking lcm and we get 11/20
then in the qn they said after 3 min proportion of R ....clearly we are knowing that (A=p),(B=Q),(C=R).
So we should consider the value of c.
To calculate the proportion of R after 3 min,
Now part filled by C in 3 min is 3x(1/10)=3/10,
the proportion of R=total filled /c filled,
= (3/10)x(20/11),
= 6/11.
Part filled by B in one min is given by=1/20 min.
Part filled by C in one min is given by=1/10 min.
Now, total (A+B+C)filled in 1 min is given as (1/30+1/20+1/10) by taking lcm and we get 11/20
then in the qn they said after 3 min proportion of R ....clearly we are knowing that (A=p),(B=Q),(C=R).
So we should consider the value of c.
To calculate the proportion of R after 3 min,
Now part filled by C in 3 min is 3x(1/10)=3/10,
the proportion of R=total filled /c filled,
= (3/10)x(20/11),
= 6/11.
(3)
Vignes R said:
7 years ago
If pipe c is empty the tank. Put negative sign Why use + sign?
(1)
Shailesh Vishwakarma said:
7 years ago
A = 30min fill 100%.
B = 20min fill 100%.
C = 10min fill 100%.
if 3 min filling done all together then,
A =3min fill 10%,
B =3min fill 15%,
C =3min fill 30%.
P =10%,
Q = 15%,
R = 30%.
Total = 55% total tank filled.
Proportion of soln R in total liquid,
=R/Total,
=30/55,
=6/11.
B = 20min fill 100%.
C = 10min fill 100%.
if 3 min filling done all together then,
A =3min fill 10%,
B =3min fill 15%,
C =3min fill 30%.
P =10%,
Q = 15%,
R = 30%.
Total = 55% total tank filled.
Proportion of soln R in total liquid,
=R/Total,
=30/55,
=6/11.
(1)
Anitha said:
7 years ago
C spend max time 10 minutes.
So, 3/10 minutes.
(3/10)*(20/11).
6/11.
So, 3/10 minutes.
(3/10)*(20/11).
6/11.
Amit ravanak said:
7 years ago
How 6/11?
Please explain in detail.
Please explain in detail.
Guruprasad R said:
7 years ago
How 11/60? please explain.
Rohit said:
6 years ago
LCM of 20,30 and 60 are but ratio 3,2 and 1 and their lcm is 6 which is diveded as by 2,3,6 respectively. Now sum is 11 and after 3 minutes q {3} 3+3 =6 /11
Abey said:
6 years ago
How 3/10? Please explain.
Satya said:
6 years ago
Why made reciprocal of 11/20? Please explain it.
(2)
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