a) To reach her goal of saving $1600 by the end of June 2023, Sarah will need to find ways to increase her income and/or decrease her expenses. One option she could consider is taking on additional part-time work in addition to her current job. This would increase her total income and accelerate her savings rate. She could also look for ways to reduce her expenses, such as cutting back on non-essential purchases or finding ways to save money on the things she needs.
b) Without knowing the specifics of Sarah's income and expenses, it's difficult to provide an exact breakdown of her adjusted budget for this period of time. However, Sarah will need to earn and save an additional $533 per month in order to reach her goal of $1600 by June 2023. This means that she will likely need to make some adjustments to her spending and/or earning in order to meet her goal. For example, she could look for ways to increase her income by taking on additional work or finding ways to save money on her expenses by cutting back on unnecessary purchases or finding more affordable alternatives.