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Bunuel
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A can do 50% more work as B can do in the same time. B alone can do a 27 May 2022, 08:15
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C
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35% (medium)

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77% (02:00) correct 23% (02:05) wrong based on 115 sessions

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A can do 50% more work as B can do in the same time. B alone can do a piece of work in 20 h. A, with the help of B, can finish the same work in how many hours ?

(A) 13 1/3 hours
(B) 12 hours
(C) 8 hours
(D) 5 1/2 hours
(E) 5 hours
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C
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A can do 50% more work as B can do in the same time. B alone can do a Updated on: 27 May 2022, 09:11
Originally posted by ThatDudeKnows on 27 May 2022, 08:26.
Last edited by ThatDudeKnows on 27 May 2022, 09:11, edited 1 time in total.
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Bunuel
A can do 50% more work as B can do in the same time. B alone can do a piece of work in 20 h. A, with the help of B, can finish the same work in how many hours ?

(A) 13 1/3 hours
(B) 12 hours
(C) 8 hours
(D) 5 1/2 hours
(E) 5 hours
Show more

On rates questions that don't tell you what the job is, rather than working with fractional jobs, the best approach is to just make up some definition of the job (I call these "Hidden Plug Ins"). Let's make this one solving 40 GMAT questions. B can do it in 20 hours, so B can solve 2 questions per hour. A works 50% faster, so A can solve 3 questions per hour. A and B together can solve 5 questions per hour. How long does it take them to solve 40 questions? 40/5 = 8

Answer choice C.


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A can do 50% more work as B can do in the same time. B alone can do a 27 May 2022, 08:50
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ThatDudeKnows
Bunuel
A can do 50% more work as B can do in the same time. B alone can do a piece of work in 20 h. A, with the help of B, can finish the same work in how many hours ?

(A) 13 1/3 hours
(B) 12 hours
(C) 8 hours
(D) 5 1/2 hours
(E) 5 hours

On rates questions that don't tell you what the job is, rather than working with fractional jobs, the best approach is to just make up some definition of the job (I call these "Hidden Plug Ins"). Let's make this one solving 40 GMAT questions. B can do it in 20 hours, so B can solve 2 questions per hour. A works 50% faster, so A can solve 3 questions per hour. How long does it take A to solve 40 questions? 40/3 = 13.333

Answer choice A.


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Hi,

I belive we have to find combined hours of A and B to do the work that B completes in 20 hours.

Correct me If I misunderstood the question.

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A can do 50% more work as B can do in the same time. B alone can do a Updated on: 27 May 2022, 09:14
Originally posted by ThatDudeKnows on 27 May 2022, 08:57.
Last edited by ThatDudeKnows on 27 May 2022, 09:14, edited 2 times in total.
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Bunuel
A can do 50% more work as B can do in the same time. B alone can do a piece of work in 20 h. A, with the help of B, can finish the same work in how many hours ?

(A) 13 1/3 hours
(B) 12 hours
(C) 8 hours
(D) 5 1/2 hours
(E) 5 hours

On rates questions that don't tell you what the job is, rather than working with fractional jobs, the best approach is to just make up some definition of the job (I call these "Hidden Plug Ins"). Let's make this one solving 40 GMAT questions. B can do it in 20 hours, so B can solve 2 questions per hour. A works 50% faster, so A can solve 3 questions per hour. How long does it take A to solve 40 questions? 40/3 = 13.333

Answer choice A.


ThatDudeKnowsHiddenPlugIn
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Hi,

I belive we have to find combined hours of A and B to do the work that B completes in 20 hours.

Correct me If I misunderstood the question.

Posted from my mobile device
Show more


Oy!!! Suuuuuch a silly mistake on my part!! I edited my earlier post. :facepalm_man: :facepalm_man: :facepalm_man:
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Schools: Schulich Sep'22 Intake (S) Rotman '25 (S)
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A can do 50% more work as B can do in the same time. B alone can do a 27 May 2022, 09:03
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Bunuel
A can do 50% more work as B can do in the same time. B alone can do a piece of work in 20 h. A, with the help of B, can finish the same work in how many hours ?

(A) 13 1/3 hours
(B) 12 hours
(C) 8 hours
(D) 5 1/2 hours
(E) 5 hours
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Work=Rate×time

Rate of B = 1/20

Rate of A = 3/40 ((3/2) * (1/20))


Combined rate = 1/20 + 3/40 = 1/8

Time needed for A and B together is therefore 8 hours.

My Ans is 8 hours

Please guide me if I missed anything here.

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A can do 50% more work as B can do in the same time. B alone can do a 13 Dec 2025, 09:57
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