
1) Considering that Flo has a goal of walking 12,000 steps per day and 1 day has 24 hours we can write out the following relation:

So Flo walks a total of 12,000 per 1440 minutes.
2) On the other hand, Flo has a routine of 6,000 steps per day and since her speed is 100 steps per minute, we can write out the following:

Note that since Flo walks 100 steps per minute, to fulfill her goal she must walk in a day 120 steps per minute.
Since she usually does 6000 steps/day we can write out a proportion and then find the following ratios.
So, Flo needs an extra walking of 50 minutes