On Thursday afternoon, two machines, J and R, ran continuously at unif

Question

On Thursday afternoon, two machines, J and R, ran continuously at uniform rates to fill a production order. How long did it take them to fill the order?
 
(1) Machine R produces 6 orders per hour.
(2) Machine J produces 4 orders per hour.

pushpitkc · Answer

(1) Machine R produces 6 orders per hour.
Knowing just the number of orders Machine R is not enough to know how long it 
took both of them to fill the order  (Insufficient)

(2) Machine J produces 4 orders per hour. 
Knowing just the number of orders Machine J is not enough to know how long it
took both of them to fill the order.  (Insufficient)

Without knowing the size of production order, even though we know the individual
rates at which the machines work, we can't give the time taken to finish the total
order  (Insufficient - Option E)

vaibhav3005 · Answer

The production rates of both the machines are specified but then, the question doesn't mention the order size which needs to be completed. So, I believe nothing can be said about the time taken as long as this data is missing. Hence, the correct answer should be  Option E .

vaibhav3005 · Answer

Could you please help me with how you concluded that both the sentences combined would give us the solution even when the order size itself is unknown? Thank you.

AK92 · Answer

The problem can be solved with the 2 machine work formula: A*B/A+B
1) Gives us only the information of the rate of one machine
2) Same applies to statement 2
Combined we can set up the formula J*R/J+R=6*4/6+4=2.4, which is not necessary as soon as you know you have a 2V2E here.
The two rates are sufficient to solve.

mohshu · Answer

stat1: no info abt J,,,not suff

stat2: no info abt R ,,not suff

no info about the order a production order can contain,, option E

MvArrow · Answer

I think that a lot of people are getting this question wrong becuse they assume that "an order" means ONE ORDER.
In fact I would suggest to change it with "an order of a particular size" for example...

dharmik · Answer

Answer: E, because the question doesn't mention how many orders are to be completed, therefore insufficient aka E.

anhht13 · Answer

I think that many people forgot that an important point: you have to know the size of "a production order" that two machines, J and R, ran continuously at uniform rates to fill. We have:

(1) Machine R produces 6 orders per hour.
(2) Machine J produces 4 orders per hour.

=> we only know that in 1 hour, 2 machine can produce 10 orders. But the question doesn't say anything about how many orders are there in "a production order" that 2 machine have to fill. This "production order" can contain 1, 2 or even 100 orders => hence we can't conclude anything about "How long did it take them to fill the order?".

mekoner · Answer

It is given from the STEM that both machines have uniform rates, we just don't know the size of the order

mbit · Answer

I answered C. I can understand why E, but if the answer to this question is E, what can we safely assume? Replacing "production order" (in stem) with "orders" in prompts seems to imply 6 "orders"/hr = 6 "production orders"/hr. If we cannot safely assume that, what can we assume. For instance:

Rob and John eat sandwiches at an a constant rate. How long does it take Rob and John to eat 10 sandwiches?

1) Rob eats 6 sandwiches/hour
2) John eats 4 sandwiches/hour

Answer) E, because the stem doesn't specify what type of sandwiches, and nothing in the prompts states that they are eating the same sandwiches or that those sandwiches are the sandwiches that the stem is referring to. (Stem could be asking about 8 inch, meatball subs. John could have been eating 12 inch sandwiches with extra meat, Rob could have been eating 6 inch veggie sandwiches.) Would this be the correct answer?

amanvermagmat · Answer

Hi In your example of Rob and John eating sandwiches, it is perfectly clear that answer should be C. If the question doesnt say anything else, we can safely assume that the sandwiches are same as being talked about earlier. The question didnt specify that there were different sized sandwiches, so we have to take that to mean that all sandwiches are the same (this thought of 8 inch subs, 12 inch sandwiches etc shouldnt even arise in our heads

)

TommasoP · Answer

This question seems a little poorly phrased to me imho. It uses "order" to mean different things

On Thursday afternoon, two machines, J and R, ran continuously at unif

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On Thursday afternoon, two machines, J and R, ran continuously at unif

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