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Sub 505 (Easy)|   Work and Rate Problems|                     
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Bunuel
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from statement 1 , we get to know both the rates of X and Y. so sufficient
from statement 2 , we know that x and y will take 1 hour combined as rate of x is given 2 hours which is double the combined rate. so sufficient
correct answer - D
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[b]SOLUTION[/b]

Machine X runs at a constant rate and produces a lot consisting of 100 cans in 2 hours. How much less time would it take to produce the lot of cans if both Machines X and Y were run simultaneously?

Machine X produces 100 cans in 2 hours --> the rate of X is (rate) = (job)/(time) = 100/2 = 50 cans per hour.

(1) Both Machines X and Y produce the same number of cans per hour --> so we know both the rates of X and Y. Sufficient.

(2) It takes Machine X twice as long to produce the lot of cans as it takes Machines X and Y running simultaneously to produce the lot. Since Machine X takes 2 hours to produce the lot, then both Machines X and Y would take 1 hour to produce the lot. Sufficient.

Answer: D.

Hi Brunei ,

For option 2 : Why Ta = 1 and Tb = 1 . Why not Ta=1.5 and Tb = 0.5 . Could you please explain by equations.
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Bunuel
[b]SOLUTION[/b]

Machine X runs at a constant rate and produces a lot consisting of 100 cans in 2 hours. How much less time would it take to produce the lot of cans if both Machines X and Y were run simultaneously?

Machine X produces 100 cans in 2 hours --> the rate of X is (rate) = (job)/(time) = 100/2 = 50 cans per hour.

(1) Both Machines X and Y produce the same number of cans per hour --> so we know both the rates of X and Y. Sufficient.

(2) It takes Machine X twice as long to produce the lot of cans as it takes Machines X and Y running simultaneously to produce the lot. Since Machine X takes 2 hours to produce the lot, then both Machines X and Y would take 1 hour to produce the lot. Sufficient.

Answer: D.

Hi Brunei ,

For option 2 : Why Ta = 1 and Tb = 1 . Why not Ta=1.5 and Tb = 0.5 . Could you please explain by equations.

We are told that Machine X produces 100 cans in 2 hours.

(2) says that "It takes Machine X twice as long to produce the lot of cans as it takes Machines X and Y running simultaneously to produce the lot".

Since Machine X takes 2 hours to produce the lot, then both Machines X and Y would take 1 hour to produce the lot.
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Can someone help solving option 1. I know the rates become same. How to solve further?
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