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3 years ago

9

David can finish painting the room in 6 hours, and his elder brother Antony can finish it in 4 hours. If both brothers paint the

room together, how many hours will it take them?

1 answer:

erica [24]3 years ago

7 0

Answer:

Step-by-step explanation:

1/6+1/4=5/12

5/12 of the job is done in 1 hour

so

5/12+5/12= 10/12

so 10/12 of the job is done in 2 hours

and then simplify 5/6 so then add 1/6

so it is done in 2 hours and 24 minutes

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The given length of fencing is $90 m$ .

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Check this point by double differentiation

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$A=\frac{135}{2}\times \frac {15}{2}-\frac{9}{2}\times \left(\frac {15}{2}\right)^2$

$\Rightarrow A=253.125 m^2$

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