Factory line A assembles materials and makes leather bags at a rate of

Question

Factory line A assembles materials and makes leather bags at a rate of 25 bags/hour. Exactly an hour later, factory line B starts production of leather bags at a rate of 30 bags/hour. In how many minutes after line B started production, will the two factory line have produced the same number of leather bags?

(A) 5
(B) 11
(C) 250
(D) 300
(E) 360

(A) 5
(B) 11
(C) 250
(D) 300
(E) 360

sarphant · Accepted Answer

The relative rate of Factory B is (30 - 25) = 5 bags/hr
and Since the factory B starts after an hour it justs have to outweight whatever A made in an hour which is 25 bags
So 25/rel rate = 25/5 = 5 hrs = 300 min.

lacktutor · Answer

A—25 bags/hour
B—30 bags/hour

A started producing an hour earlier than B

25t+ 25= 30t
t = 5 hours
5 *60 minutes = 300

The answer choice is D

Posted from my mobile device

DarshanK · Answer

Answer can be solved by logic.

The first machine starts its production an hour prior to the second machine but is comparatively slower than the second one. 
 
At 6 hours, Machine A would have produced 25x6= 150
Machine B having started an hour later would have produced only for 5 hours, 5x30=150

So at 360 minutes both the machine would have the same production.

stne · Answer

Hi  lacktutor ,
Why is the answer not coming this way 25t= 30(t-1)
25t=30t-30
5t=30 ,t=6

Shouldn't the answer come this way too.

lacktutor · Answer

Why not??

But, you need to calculate it correctly. The question is asking the total time after B starts, not A. 
In your case, (t-1) is the right one. 
—> 6-1=5 or 300 minutes.

Hope it helps

stne · Answer

Hi  lacktutor ,

Where in the question does it say total time taken by B?

bcl · Answer

DarshanK , since the question asks "In how many minutes" it implies that it is asking only for the time from 'now', which is when B starts running. Thus, it's not the total time but t-1hr or 300 minutes. It could be written more clearly.

ScottTargetTestPrep · Answer

Let n = the number of hours that line B has been in production. Since line A started production 1 hour prior to line B, its time in production is n + 1 hours. We can use the equation:

25(n + 1) = 30n

25n + 25 = 30n

25 = 5n

5 = n

So, the same number of bags are produced in 5 x 60 = 300 minutes.

Answer: D

vishumangal · Answer

Hi,

As per the below solution, U have calculater the number of hrs B take, but in question its talking about the number of hrs two factory lines will take.

So if we calculate the numbers of factory line A has worked is 360 mins.

Seems like this question is poorely written.

Both 360 and 300 can be the ans depending upon the inference of a test taker

Posted from my mobile device

stne · Answer

Hi  vishumangal , 
You are correct
That was precisely my query, one should be honest about one's reply rather than formulate the explanation to suit the OA.
IMO there is no way we can be sure whether total time from beginning or time taken after B starts , is being asked for here.
if any moderator can correct me , I would be grateful.

Bunuel · Answer

Edited the stem to make the question less ambiguous.

Hope now the question is fine.

stne · Answer

Thank you sir, now everything looks awesome!

Archit3110 · Answer

from given info
we have
25*(x+1)=30x
x= 5 hrs or say 300 mins
IMO D

Kinshook · Answer

Let the time after line B started production, will the two factory line have produced the same number of leather bags = x hours
30x = 25x + 25
5x = 25
x = 5 hours = 300 minutes

IMO D

TheNightKing · Answer

B is making 5 more than A. A is already ahead in the game with 25 bags. B will take 5 hours to make those 25 bags. 5 hours is 300 minutes. Hence D

bumpbot · Answer

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Factory line A assembles materials and makes leather bags at a rate of

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