One pipe can fill a tank three times as fast as another pipe. If together the two pipes can fill the tank in 36 minutes, then the slower pipe alone will be able to fill the tank in:
[A].
81 min.
[B].
108 min.
[C].
144 min.
[D].
192 min.
Answer: Option A
Explanation:
Let the slower pipe alone fill the tank in x minutes.
Why cant we take 3x for faster pipe and x for slower pipe? if I take in that way im getting answer as 9. Is it right or wrong?.
Pri said:
(Wed, Jan 26, 2011 09:33:55 PM)
Please expain this solution more clearly.
Reshma said:
(Tue, Feb 22, 2011 07:48:34 AM)
@Pranathi.
We are discussing about d time. If we take the time taken by slower pipe as x and faster time pipe as 3x. It means that faster pipe takes more time. Which means our assumption is wrong.
Karthiga said:
(Thu, Feb 24, 2011 08:55:26 PM)
Why we take 1/x+3/x instead of x + x/3 =36 ?
Miss Mathphobia said:
(Wed, Mar 30, 2011 10:01:08 AM)
Why not x+x/3=36?
It gives me answer as 27...
Anusha said:
(Sun, May 15, 2011 08:34:13 AM)
its simple ya , one pipe =1/x;
anther pipe =3/x:
=4x36 sec=144.
comment pls.
Manasa said:
(Sat, Jun 11, 2011 09:22:56 AM)
Thanks RESHMA.
Sonu Choudhary said:
(Sat, Jun 25, 2011 04:04:21 PM)
I am still not understand why we take 1/x+3/x=1/36. Please reply.
Vinoth Kumar said:
(Wed, Jun 29, 2011 08:10:01 AM)
@sonu:
if A takes x mins
given tat B works thrice as fast as A
i.e, B takes 1/3 of A's time=x/3
we know tat
1/A+1/b=1/36
1/x+1/(x/3)=1/36
1/x+3/x=1/36
4/x=36
x=4*36
x=144
Rishab said:
(Wed, Aug 3, 2011 11:47:40 PM)
How do we know that 1/a + 1/b = 1/36 ?
Bhushan said:
(Mon, Aug 8, 2011 02:06:41 PM)
Above ans is right. Thing this way.....we want to find the time that the slower pipe alone can fill the tank not the time from total 36mins hence we take 1/A+1/b=1/36 so that we are finding the time from 100% and not from 36 mins. We are basically generalizing by taking the numerator as 1.
Poornima said:
(Mon, Aug 8, 2011 05:43:09 PM)
Why do we need to take time as 1/time?
Kailash said:
(Mon, Aug 15, 2011 12:11:24 AM)
Whenever we say ram works twice as fast as shyam in a given timeframe. it means it takes two shyams to complete that work in that given timeframe because single shyam can only do half of ram's capacity. kindly always keep this common sense in mind while attempting these kind of ques independent of their form.
So solution: one pipe works 3 times faster than other..let name of this pipe A
let name of other pipe (slower)B
B is equivalent to shyam here..so if both pipes can fill one tank in 36 mins. both means A+B and as per our common sense A is equivalent to 3 B's. therefore
(B+B+B)+B = 36
B = 36/4? NOT POSSIBLE
as if 4 people can do a work in 1 min then 1 person will do it in 4*1 mins. coz more people less time and less people more time.
What we understand by this is timse is inversely proportional to work done. therefore if four B's doing it in 36 mins then single B will do it in 4*36 = 144.
Dolo said:
(Thu, Aug 25, 2011 05:58:39 PM)
Great kailash.
Jamloki said:
(Fri, Aug 26, 2011 11:50:07 PM)
Kailash you are genious.
Saurav said:
(Mon, Sep 12, 2011 08:18:34 PM)
If i take A =x and B=3x then I am getting 27 min as answer is it wrong?
If I assume x as time then A = 9 and B =27 after calculating x+3x=36 is it wrong? please explain.
Laxman said:
(Sun, Sep 18, 2011 12:20:49 AM)
The simplest way is.
Together the two pipes can fill in 36 min.
That means the fastest one can fill 36*3=108.
And the slowest one is =108+36=144.
Shanti Lal Dhaker said:
(Tue, Oct 18, 2011 04:20:14 PM)
We may also solve in this manner i.e.
x + x/3 =36
=>
4x/3 = 36
or =>
x=27
Teju M.B said:
(Sun, Nov 13, 2011 03:17:45 AM)
@Laxman:.
Your way of approaching to the problem is good, simple and understandable.
