Pump A can empty 1/A in 1 minut, so for 2 pumps the remaining work to be done is 1-1/A. If time T is calculated from the time when pump B joins, the equatation will be like T(A+B)/AB =1-1/A. Once we get T value from here, we can add 1 (minut) which Pump A has already worked before Pump B joins, we will get answer B.
This is very helpful Erika. You go through the calculation in depth, not assuming the viewer would know or understand. Very useful for me. You're doing God's work 🙏🏼
Hey Erika, If you can share some tips on how to improve data sufficiency or a video on how to approach data sufficiency questions would be very helpful specially questions which involves range type of questions in arithmetic and inequalities in algebra
Glad you liked it! Lots of study and practice goes into becoming an expert like this :) But you can certainly get there! We're glad to have you around!
Thank you Erika! I had one question. Is there any other way to solve the hard Magoosh example problem without the table if we translate each of the statements into equations?
Hi Erika...great stuff on solving this question. I was wondering whether it is possible in this question to eliminate the answer choices by analyzing the units of the choices ?? [A(B+1)] / (A+B) becomes incorrect then as after cancellation the unit of the result becomes minute + 1 A*B / (A+B) then becomes correct as after cancellation the unit of the result is minute
Hi Sanish, creative idea! Unfortunately it won't work in this case. We know, for instance, that "Pump A can empty the pool in A minutes." This means that A is just a number, it doesn't have any units. So A = 30 would fit in the sentence, but A = 30 minutes would not work, since "minutes" would be repeated. So the units are already specified and the variables are just numbers, so every choice will have the same result in terms of units.
I'm sorry but could you help me? I can't see my mistake I did the following (X+1)/A + X/B = 1 B(X+1) +AX = AB BX + B + AX = AB X(A+B) = AB - B Answer: X = (AB-B)/(A+B) OR B(A-1)/(A+B)
Hi Erika, the problem states that pump A began 1 minute before pump B, I don’t think I would have come up with 1 as being the time for row 1 in your table. It seemed to me that starting one minute earlier, played some role. Will you please help me understand how 1 minute earlier is simply the time for pump A? Help!!
Sorry isn't W of (A and B) not =1? Because the W of B would be 2/3 so since W of A= 1/3 then WA+WB=1. Then we would be using in the line of the table R for (A and B) but W for B alone. What am I not seeing here?
"A" has a rate 1/3 pumps per minute, so after 1 minute, the W done is 1/3 (of the pool) by A ALONE. That leaves 2/3 of the pool left to do for A and B TOGETHER. Hope that helps! 😃
Pump A can empty 1/A in 1 minut, so for 2 pumps the remaining work to be done is 1-1/A. If time T is calculated from the time when pump B joins, the equatation will be like T(A+B)/AB =1-1/A. Once we get T value from here, we can add 1 (minut) which Pump A has already worked before Pump B joins, we will get answer B.
This is very helpful Erika. You go through the calculation in depth, not assuming the viewer would know or understand. Very useful for me. You're doing God's work 🙏🏼
Woohoo! We're glad you found it useful :) More will be coming!
These tables for work and distance problems are so useful in staying organized.
We're glad you find them useful!
Hey Erika, If you can share some tips on how to improve data sufficiency or a video on how to approach data sufficiency questions would be very helpful specially questions which involves range type of questions in arithmetic and inequalities in algebra
We will certainly make more along those lines so will keep this suggestion in mind! Thanks for sharing :)
Hey, Erika! This was super helpful. Could you solve a couple of difficult distance problems as well? Thanks.
We're glad you liked this one! More will be on the way in the future :)
You might also enjoy this video!
ua-cam.com/video/37x-QAfNDJw/v-deo.html
Thanks Erica and Magoosh !
Very insightful... organized and quick as well. Thanks!
How can you be so smart??, thankz so much!!
Glad you liked it! Lots of study and practice goes into becoming an expert like this :) But you can certainly get there! We're glad to have you around!
Thank you Erika! I had one question. Is there any other way to solve the hard Magoosh example problem without the table if we translate each of the statements into equations?
Hi Erika...great stuff on solving this question. I was wondering whether it is possible in this question to eliminate the answer choices by analyzing the units of the choices ??
[A(B+1)] / (A+B) becomes incorrect then as after cancellation the unit of the result becomes minute + 1
A*B / (A+B) then becomes correct as after cancellation the unit of the result is minute
Hi Sanish, creative idea! Unfortunately it won't work in this case. We know, for instance, that "Pump A can empty the pool in A minutes." This means that A is just a number, it doesn't have any units. So A = 30 would fit in the sentence, but A = 30 minutes would not work, since "minutes" would be repeated.
So the units are already specified and the variables are just numbers, so every choice will have the same result in terms of units.
I'm sorry but could you help me? I can't see my mistake
I did the following
(X+1)/A + X/B = 1
B(X+1) +AX = AB
BX + B + AX = AB
X(A+B) = AB - B
Answer: X = (AB-B)/(A+B) OR B(A-1)/(A+B)
Hi thankyou for your huge help❤️i don't know english well. May I take an exam in russian
Hi Erika, the problem states that pump A began 1 minute before pump B, I don’t think I would have come up with 1 as being the time for row 1 in your table. It seemed to me that starting one minute earlier, played some role. Will you please help me understand how 1 minute earlier is simply the time for pump A? Help!!
Hi Erika
What if you don’t have the rate or the time, but you have a comparison? (For example 2 people working 3 times as fast as a 3rd person?)
We'd still need more information!
Thank you😅
You're welcome! Thanks for watching! 🙌
Oh no, now I'm confused between Magoosh and Prepscholar lol
😂
i haven't tried solving the ing method before
Sorry isn't W of (A and B) not =1? Because the W of B would be 2/3 so since W of A= 1/3 then WA+WB=1. Then we would be using in the line of the table R for (A and B) but W for B alone. What am I not seeing here?
"A" has a rate 1/3 pumps per minute, so after 1 minute, the W done is 1/3 (of the pool) by A ALONE.
That leaves 2/3 of the pool left to do for A and B TOGETHER. Hope that helps! 😃