Marco is reconstructing his expenses for the past two weeks. Here are the records of his expenses:
| Transaction | Cost ($) |
| :---------- | :------- |
| T-shirt | 20 |
| Gas | 22 |
| Movie | 13 |
| Video game | 39 |
| Jeans | 34 |
| Hat | 15 |
| Books | 31 |
Marco's bank statement says that he has an ending balance of $81. What is Marco's starting balance?
A. $255
B. $93
C. $174
D. $210
Answer (1)
Calculate the total expenses: E = 20 + 22 + 13 + 39 + 34 + 15 + 31 = 174 .
Use the formula: St a r t in g B a l an ce = E n d in g B a l an ce + T o t a lE x p e n ses .
Substitute the values: S = 81 + 174 = 255 .
Marco's starting balance is 255 .
Explanation
Calculate Total Expenses We need to find Marco's starting balance given his expenses and ending balance. Let's first calculate the total expenses by summing up the cost of each transaction.
Summing Expenses The expenses are: T-shirt ($20), Gas ($22), Movie ($13), Video game ($39), Jeans ($34), Hat ($15), Books ( 31 ) . T h e t o t a l e x p e n ses E i sc a l c u l a t e d a s : E = 20 + 22 + 13 + 39 + 34 + 15 + 31 = 174 $
So, Marco's total expenses are $174.
Relating Starting and Ending Balance Let S be the starting balance and F be the ending balance. We know that the ending balance is the starting balance minus the total expenses: F = S − E . We are given that F = 81 . We need to solve for S.
Calculating Starting Balance To find the starting balance S, we rearrange the equation F = S − E to get S = F + E . Substituting the given ending balance F = 81 and the calculated total expenses E = 174 , we have: S = 81 + 174 = 255 Therefore, Marco's starting balance is $255.
Final Answer Therefore, Marco's starting balance is $255.
Examples
Imagine you're saving up for a new bicycle. By tracking your income (like your allowance or earnings from a part-time job) and subtracting your expenses (such as snacks, entertainment, or small purchases), you can determine how much money you have left at the end of each week or month. This helps you understand if you're on track to reach your savings goal for the bicycle. Similarly, businesses use this concept to manage their finances and ensure they have enough funds to cover their expenses and investments.
