Work crews Alpha and Zeta are repaving a section of freeway in Los

Question

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Work crews Alpha and Zeta are repaving a section of freeway in Los Angeles. Work crew Alpha started its work one week (40 working hours) earlier than work crew Zeta, and started on the north end of the freeway, working its way south at a rate of 12 meters per hour since starting the job. Now, work crew Zeta has started at the south end, working its way north at a rate of 10 meters per hour. The section of freeway that needs to be repaved is 1.5 kilometers long, including the section that has already been paved.

Given that each crew will not necessarily work the same number of hours, which of the following answer choices represents an hourly workload for each crew that will finish the project? Please make only one selection in each column.

Apt0810 · Answer

In 40 hours Alpha crew completed 12*40 = 480m of work
So remaining work is 1500-480= 1020 m

So 12x+10y=1020
So x=60 (Alpha crew work hours)
y=30 (Zeta crew work hours)

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sunita123 · Answer

Hi,
how did you solve this equation 12x+10y=1020 for x & y ?

akpotdar · Answer

Here the equation was 12x + 10y = 1020

For finding the value we can do hit and trial method, for example,

Let y = 10, 12x = 920
(Here 92 is not divisible by 12 so it's incorrect)

Now let y = 20, 12x = 820
(here 82 is not divisible by 12 so it's incorrect)

Now, let y = 30, 12x = 720
720 is divisible by 12 and hence it satisfies the solution

sayan640 · Answer

chetan2u   KarishmaB  Would you like to explain this question ?

Work crews Alpha and Zeta are repaving a section of freeway in Los

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Crew Alpha	Crew Zeta	Values
		10
		20
		30
		40
		50
		60