Answer:
24weeks
Step-by-step explanation:
So if she spends 5$ three times a week she spends 15$ a week
She babysits once a week for 40$
That means that she saves 25$ from babystitting each week
As she already has saved 200$, she only lacks 600$ for the purchase
600$ / (25$/week) = 24 weeks
If she stops buying coffee it will instead only take her 15 weeks to buy a new laptop