Working alone at its own constant rate, a machine seals k cartons in 8 hours,
and working alone at its own constant rate, a second machine seals k cartons in
4 hours. If the two machines, each working at its own constant rate and for the
same period of time, together sealed a certain number of cartons, what percent
of the cartons were sealed by the machine working at the faster rate?
25%
33 1/3%
50%
66 2/3%
75%
D
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two machines.
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Let k = 8 units.Ozlemg wrote:Working alone at its own constant rate, a machine seals k cartons in 8 hours,
and working alone at its own constant rate, a second machine seals k cartons in
4 hours. If the two machines, each working at its own constant rate and for the
same period of time, together sealed a certain number of cartons, what percent
of the cartons were sealed by the machine working at the faster rate?
25%
33 1/3%
50%
66 2/3%
75%
D
Rate for slower machine = w/t = 8/8 = 1 unit per hour.
Rate for faster machine = w/t = 8/4 = 2 units per hour.
When the machines work together, the number of units sealed each hour = 1+2 = 3.
(Units sealed by faster machine)/(Total units sealed) = 2/3 = 66.66%.
The correct answer is D.
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IMO: D as well,
consider k to be 10
in 4 hrs (WORKING TOGETHER),
machine 1 would have completed 5 cartons
machine 2 would have completed 10 cartons
Total cartons = 15
Machine working faster is machine 2
what percent of the cartons were sealed by the machine working at the faster rate?
15*(X/100)=10 => 66 2/3 %
consider k to be 10
in 4 hrs (WORKING TOGETHER),
machine 1 would have completed 5 cartons
machine 2 would have completed 10 cartons
Total cartons = 15
Machine working faster is machine 2
what percent of the cartons were sealed by the machine working at the faster rate?
15*(X/100)=10 => 66 2/3 %
