Respuesta :
The amount of work done by Kalon in an hour is equal to 1/4. This is based on his time to finish the job. Letting x be the number of hours Marna can finish the job alone will let her finish 1/x of the job in an hour. If their rates are added together and multiplied by the number of hours they worked together, the product should be one whole job.
(1/4 + 1/x)(1 5/7) = 1
The value of x is 3. Therefore, it will take 3 hours for Marna to clean the chimney alone.
(1/4 + 1/x)(1 5/7) = 1
The value of x is 3. Therefore, it will take 3 hours for Marna to clean the chimney alone.
Answer:
It takes 3 hours for Marna to clean the same size chimney by herself.
Step-by-step explanation:
Kalon and his friend Marna can clean a chimney in [tex]1 \frac{5}{7}= \frac{12}{7}[/tex]hours
They can do a part of work in 1 hour = [tex]\frac{1}{\frac{12}{7}} = \frac{7}{12}[/tex]
Kalon can complete work in 4 hours
He can do a part of work in 1 hour = [tex]\frac{1}{4}[/tex]
So, Marna can do a part of work in 1 hour = [tex]\frac{7}{12}-\frac{1}{4}[/tex]
= [tex]\frac{1}{3}[/tex]
So, Marna can [tex]\frac{1}{3}[/tex] part of work in hour = 1
Marna can complete work in hour = 3
Hence it takes 3 hours for Marna to clean the same size chimney by herself.