# 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?
 5 11
 6 11
 7 11
 8 11
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:
72 comments Page 1 of 8.

Saikat said:   3 months ago
Total 60 unit.

A = 1 minute 2 unit
B =1 min 3 unit
C =1 min 6 unit.

So, Total (6+3+2)=11 unit.
C contribution is 6/11 unit.
(7)

Akshay Kumar Roy said:   3 months ago
First take the LCM of all the time taken by A, B, and C which we will give us total work = 60, and then take out the efficiency by the formula (total work/time) A-> 2 ,B-> 3 and C-> 6 and then take out the Ratio of C's R liquid proportion (6/11) by multiplying both the numerator and denominator by 3.
And the result we will get is 6/11.
(1)

KS said:   4 months ago
Lcm = 60.
It means the total tank capacity is 60 liters.
A done in one min = 60/30= 2lit,
B done in one min = 60/ 20= 3 lit,
C done in one min = 60/ 10 = 6 lit,
So, Total lit in one minute = 11 lit,
So, Total lit in three mints = 11 * 3 = 33 lit,
C done in three min = 6 * 3 = 18.
C' share is after three minutes = 18/33 = 6/11 ans.
(18)

Soumitra Malo said:   1 year ago
Lcm = 60.
It means the total tank capacity is 60 lit.
A done in one min = 60/30= 2lit,
B done in one min = 60/ 20= 3 lit,
C done in one min = 60/ 10 = 6 lit,
So, Total lit in one min = 11 lit,
So, Total lit in three mints = 11 * 3 = 33 lit,
C done in three min = 6 * 3 = 18.
C' share is after three minutes = 18/33 = 6/11 ans.
(62)

Subu said:   2 years ago
Lcm = 60 .it means total tank capacity is 60 lit.
A done in one min = 60/30= 2lit,
B done in one min = 60/ 20= 3 lit,
C done in one min = 60/ 10 = 6 lit,
So Total lit in one min = 11 lit,
So Total lit in three mints = 11 * 3 = 33 lit,
C done in three min = 6 * 3 = 18.
C' share is after three mints = 18/33 = 6/11 ans.
(62)

Hritik said:   3 years ago
(4)

Saloni said:   3 years ago
Why do we reciprocal 11/20? Explain please.
(9)

Nandeesh said:   3 years ago
3/30 + 3/20 + 3/10.
(6+9+18)/60 = 33/60 = 11/20,
(3/10)/11/20 = (3/10*20/11) = 6/11.
(12)

Aman Kumar said:   4 years ago
According to me,

30, 20, 10 LCM 60 means per unit of each pipe is;

2, 3, 6 total unit = 11.

We can write this way also 60\11 *3\10 = 6\11.
(10)

Mruthyunjaya bm said:   4 years ago
Filled by C in 3 minutes = 3/10.
Filled by (A + B + C) in 3 minutes = 3 ( 1/30+ 1/20 +1/10)= 3*11/60 = 11/20.
As they told A B C proportional to P Q R (R=C).
Required ratio = chemical solution R in tank/ total chemical solution in tank.
i.e. (3/10)/(11/20),
=(3/10)*(20/11),
= (3*20)/(10*11),
= 60/110,
= 6/11.
(6)