For this case, the first thing we must do is define variables.
We have then:
x: number of hours
y: Amount of scarf that Sara knits
We then have the following equation that models the problem:
The number of hours during the 8 days is given by:
Substituting the value of x in the ada equation we have:
Answer:
she will knitted by the end of the trip about 52528mm of scarf