Final answer:
Mariah earns $40 weekly from babysitting and spends $15 on coffee, saving $25 weekly. She has $200 saved and needs $600 more for an $800 laptop, thus she needs to babysit for 24 more weeks to achieve her goal.
Step-by-step explanation:
The question at hand involves a practical application of basic mathematics to calculate how Mariah can save for a new laptop. Mariah babysits her neighbor's kids and earns $40 each time, doing this once a week, resulting in $40 per week. She then spends $15 a week on coffee ($5 per latte, three times a week). As she has already saved $200, we can calculate how many more weeks she needs to babysit to afford an $800 laptop.
The calculation is as follows:
Remaining amount needed: $800 - $200 = $600
Weekly savings: $40 (earnings) - $15 (coffee) = $25
Number of weeks needed: $600 / $25 = 24 weeks
Therefore, Mariah will need to continue babysitting for 24 more weeks to save enough for the laptop.