Jim can fill a pool carrying bucks of water in 30 minutes. Sue can do the same job in 45 minutes. Tony can do the same job in 1 ½ hours. How quickly can all three fill the pool together?
a) 12 minutes
b) 15 minutes
c) 21 minutes
d) 23 minutes
e) 28 minutes
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It is a 15 second question. Please reply with approach.
let the work done together be X
combining the rate of work done by jim ..sue and tony
X/30+ X/45+/90
=>6X/90
=>X/15
so they will take 15minutes together to get the work done
X/30+ X/45+ X/90
15 minutes.
Say the pool holds 90 gallons. Jim fills it at a rate of 3 gallons a minute; Sue at a rate of 2 gallons a minute; and Tony at 1 gallon a minute.
In 15 minutes, Jim fills 45 gallons; Sue fills 30 gallons; Tony fills 15 gallons. The pool is full.
Amazing approach Mika !
why the pedant
in me think that MIKA approach takes more time than the BILLU approach.i m lull confused , billu approach is rather more accurate.
Billu approach—————–(cnfused)———————-Mika approach
Hmmmm..
It is all about understanding of the concept.
Billu’s approach used by each and every one.
Mika’s approach used by the competitive people. Once you understand this concept you will be able to solve many questions within a second.
mika approach is hit and trial method,
u cant get the exact ans, u can only choose among the answer,
so i think getting answer in the same time is better than,
finding each option for feasiblity.
and if u use mika approach for finding the ans ultimately u have to use the billu’s formula.
so i m confused that weather i will try MIka hit and trial on 5 given option.
or by using quickly Billu formula to find the answer.
i need help here.
There is nothing like hit and trial.
You always can take LCM of all numbers. As in this case LCM of 30,45,90 is 90.
i got LCM , then after that how i come to know that ans is 15.
here we have to put all option and to see weather this will fit here or not.
am i right , or i m missing somthing really stupid here?
Here I am taking a simple example.
Jim can fill a pool carrying bucks of water in 30 minutes. Sue can do the same job in 45 minutes. Tony can do the same job in 90 munutes. How quickly can all three fill the pool together?
Say the pool holds 90 gallons (Because LCM of 30, 45 and 90 is 90). Jim fills it at a rate of 3 gallons a minute; Sue at a rate of 2 gallons a minute; and Tony at 1 gallon a minute.
All three fill 3+2+1= 6 gallons a minute.
If all three work together they will take 90/6= 15 minutes.
Great Method GRE TEam ….
But I still believe … one should do solve the question with the method with he/she is comfortable with ….
I ‘m more comfortable with billu’s method since I m used to wit tat method ….although it might be second slower …
There is more chance of making a silly mistake if u suddenly try to solve a ques. with a new method without enough previous practice ….
But I still believe … one should do solve the question with the method with he/she is comfortable with…
>>> That is great !. I am also agreed.
I ‘m more comfortable with billu’s method since I m used to wit tat method ….although it might be second slower …
>>> I know that more than 90% people follow billu’s method since it is adopted from school level.Even though it is time consuming.
There is more chance of making a silly mistake if u suddenly try to solve a ques. with a new method without enough previous practice ….
>>> If you are not going to apply new best practices. How you are going to achieve comfort zone in real GRE test.
> If you are not going to apply new best practices. How you are going to >achieve comfort zone in real GRE test
I dont think achieving comfort zone necessarily requires adopting new practices …
and as far as best practices is concerned … as i said, one should follow his method with he/she is comfortable with, rather than best practice ….
If you learn the best 20 ways to crack math GRE questions and able to save 5-7 minutes. It makes more sense. In place of using rather old way to crack a quetions within time limit.
Jim can fill a pool carrying bucks of water in 30 minutes. Sue can do the same job in 45 minutes. Tony can do the same job in 1 ½ hours. How quickly can all three fill the pool together? If Tony left the job after 5 days.
Homer too Nods!!!!!! !:) A small correction in the above question
Jim can fill a pool carrying bucks of water in 30 minutes. Sue can do the same job in 45 minutes. Tony can do the same job in 1 ½ hours. How quickly can all three fill the pool together? If Tony left the job after 5 minutes
Its 17.
3 of the people could able to do the job in 15 min.
2 of the people [if tony is not there] can finish the job in 18 minutes.
So there is gain of 3 minutes ,if Tony Joins the Team and works for 15 minutes
So if he works for only 5 minutes he could have made a gain only for 1 minute
So 18-1=17 minutes
gud approach ram…
good approach fella
Taking HCF of 30,45, and 60 would give me the answer as well
ram approach is very cooool