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Sedaia [141]
2 years ago
13

Sarah’s mom took 3 hours to clean, but when Sarah helped, it took them 2 hours to clean. How many hours will it take Sarah to cl

ean herself?
Mathematics
2 answers:
Aleonysh [2.5K]2 years ago
6 0

Answer:

<em>It takes them 1.875 hours.</em>

<em></em>

<em>Step-by-step explanation:</em>

<em></em>

<em>Here, the job is cleaning the house.</em>

<em></em>

<em>Mom does 1 job in 3 hours.</em>

<em></em>

<em>In 1 hour, mom does 1/3 of the job.</em>

<em></em>

<em>Dad does 1 job in 5 hours.</em>

<em></em>

<em>In 1 hour, dad does 1/5 of the job.</em>

<em></em>

<em>Mom and dad working together do the job in x hours.</em>

<em></em>

<em>In 1 hour, mom and dad together do 1/x of the job.</em>

<em></em>

<em>1/3 + 1/5 = 1/x</em>

<em></em>

<em>5/15 + 3/15 = 1/x</em>

<em></em>

<em>8/15 = 1/x</em>

<em></em>

<em>8x = 15</em>

<em></em>

<em>x = 15/8 = 1.875</em>

<em></em>

<em>Answer: It takes them 1.875 hours.</em>

your welcome

Savatey [412]2 years ago
4 0
1 hour.
hope this helps!
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