word problem

Question

working with your cousin, you can refinish a table in 4 hours. working alone, your cousin can complete the job in 20 hours. how long would it take you to refinish the table working alone

Answer 1

Let x = the number of hours for me to refinish the table working alone

 

When working together, the job is finished in 4 hours.

 

4/20 or 1/5 is the fractional portion of the work done by the cousin.

 

4/x is the fraction portion done by me.

 

1/5 + 4/x = 1   

 

4/x = 1 - 1/5

 

4/x = 4/5

 

x = 5 hours for me to refinish table working alone.