1. The problem asks for the total time Maria wastes on social media in four weeks, in seconds. 2. First, convert the daily time from hours and minutes to seconds. Maria wastes 5 hours and 30 minutes daily. 3. Convert 5 hours to seconds: $$5 \text{ hours} = 5 \times 60 \times 60 = 18{,}000 \text{ seconds}$$ 4. Convert 30 minutes to seconds: $$30 \text{ minutes} = 30 \times 60 = 1{,}800 \text{ seconds}$$ 5. Total daily time in seconds: $$18{,}000 + 1{,}800 = 19{,}800 \text{ seconds}$$ 6. There are 7 days in a week, so in four weeks there are: $$4 \times 7 = 28 \text{ days}$$ 7. Multiply daily seconds by total days to get total seconds wasted in four weeks: $$19{,}800 \times 28 = 554{,}400 \text{ seconds}$$ 8. The correct answer is b. 554 400 seconds.