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A worker can load 1 full truck in 6 hours. A second worker can load th
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03 May 2021, 10:40
03 May 2021, 10:40
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A worker can load 1 full truck in 6 hours. A second worker can load the same truck in 7 hours. If both workers load one truck simultaneously while maintaining their constant rates, approximately how long, in hours, will it take them to fill 1 truck?
A. 0.15
B. 0.31
C. 2.47
D. 3.23
E. 3.25
A. 0.15
B. 0.31
C. 2.47
D. 3.23
E. 3.25
Re: A worker can load 1 full truck in 6 hours. A second worker can load th
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03 May 2021, 11:27
03 May 2021, 11:27
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R*t = W
Worker 1: x*6 = 1, x = 1/6
Worker 2: x*7 = 1, x = 1/7
Worker 1+2: 1/6 + 1/7 * x = 1
13/42 * x = 1
x = 3.23
Worker 1: x*6 = 1, x = 1/6
Worker 2: x*7 = 1, x = 1/7
Worker 1+2: 1/6 + 1/7 * x = 1
13/42 * x = 1
x = 3.23
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Re: A worker can load 1 full truck in 6 hours. A second worker can load th
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03 May 2021, 12:44
03 May 2021, 12:44
1
Carcass wrote:
A worker can load 1 full truck in 6 hours. A second worker can load the same truck in 7 hours. If both workers load one truck simultaneously while maintaining their constant rates, approximately how long, in hours, will it take them to fill 1 truck?
A. 0.15
B. 0.31
C. 2.47
D. 3.23
E. 3.25
A. 0.15
B. 0.31
C. 2.47
D. 3.23
E. 3.25
One approach is to assign a nice value to the entire job (of filling a truck)
We want a number that works well with the given times (6 hours and 7 hours)
42 is such a number.
So, let's say that filling the truck is equivalent to shoveling 42 scoops of dirt into it.
A worker (we'll call worker A) can load 1 full truck in 6 hours
Rate = output/time = 42 scoops/6 hours = 7 scoops/hour
So, worker A's RATE is 7 scoops/hour
Worker B) can load 1 full truck in 7 hours
Rate = output/time = 42 scoops/7 hours = 6 scoops/hour
So, worker B's RATE is 6 scoops/hour
So, their COMBINED rate = 7 scoops/hour + 6 scoops/hour
= 13 scoops/hour
Worker B) Approximately how long, in hours, will it take them to fill 1 truck?
Time = output/rate
= 42 scoops/13 scoops/hour
= 42/13 hours
= 3 3/13 hours
ASIDE: Notice that 3 3/12 hours = 3.25 hours
So, 3 3/13 hours will equal a little less than 3.25 hours
Answer: D
Cheers,
Brent
