Answer:
8 minutes
Explanation:
The time Luis spent walking = 16 minutes
The time Natalie spent walking = w minutes
Luis walked twice as long as Natalie.
Twice means 2 times of something.
This means that we multiply Natalie's time by 2 to get Luis' time.

Next, the equation is solved to see how long Natalie walked.

The time Natalie spent walking is 8 minutes.