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3 years ago

Kevin, can clean a stadium in 5 hours working alone. Chris, can

Mathematics

1 answer:

LenaWriter [7]3 years ago

5 0

Answer: It will about 1.88 hours or 1 hour 52.5 minutes to clean the stadium if they work together .

Step-by-step explanation:

Given : Time taken by Kevin to clean a stadium = 5 hours

Rate of work done by Kelvin = $\dfrac{1}{5}$

Time taken by Chris to clean a stadium = 3 hours

Rate of work done by Chris = $\dfrac{1}{3}$

Let t be the time taken by both of them to clean the stadium together.

According to the question , we have

Rate of work done together = Rate of work done by Kelvin+Rate of work done by Chris

$\dfrac{1}{t}=\dfrac{1}{5}+\dfrac{1}{3}\\\\ \Rightarrow\ \dfrac{1}{t}=\dfrac{3+5}{15}\\\\ \Rightarrow\ \dfrac{1}{t}=\dfrac{8}{15}\\\\\Rightarrow\ t=\dfrac{15}{8} =1.875$

$t=1+0.875$ hours

$t=1\text{ hour }+0.875(60)\text{ minutes}$ [∵ 1 hour = 60 minutes]

$t=1\text{ hour }+52.5\text{ minutes}= \text{1 hour 52.5 minutes}$

Hence, It will about 1.88 hours or 1 hour 52.5 minutes to clean the stadium if they work together .

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Answer:

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Step-by-step explanation:

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d²V/dx² = 24(2.5) - 120

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3 years ago

If x=-3 is (x-5)(x-7)<0?

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Answer: False

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One year, in school A, 162 students leave and 109 go to university. In school B, 75 students leave and 68 go to university. Comp

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Answer:

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Step-by-step explanation:

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