Brittany opened a bank account and deposited some money. She then added the same amount of money each week to her bank account. The table shows the amount of money Brittany will have at the end of x weeks.


Brittany's Bank Account

Weeks 1 2 3 4
Amount (dollars) $112 $124 $136 $148

How much money did Brittany open her account with, and how much money did she deposit each week?
Responses
A Brittany opened the account with $12 and added $100 each week.Brittany opened the account with $12 and added $100 each week.
B Brittany opened the account with $25 and added $50 each week.Brittany opened the account with $25 and added $50 each week.
C Brittany opened the account with $100 and added $12 each week. Brittany opened the account with $100 and added $12 each week.
D Brittany opened the account with $50 and added $25 each week.

1 answer

To find out how much money Brittany initially deposited and how much she added each week, we can analyze the table data.

The amounts after each week are as follows:

  • After 1 week: $112
  • After 2 weeks: $124
  • After 3 weeks: $136
  • After 4 weeks: $148

We can see the difference in the amounts from one week to the next:

  • From Week 1 to Week 2: $124 - $112 = $12
  • From Week 2 to Week 3: $136 - $124 = $12
  • From Week 3 to Week 4: $148 - $136 = $12

This shows that Brittany deposits $12 each week.

Next, we will use the information about the total amounts and the weekly deposits to find out how much she started with (let's call the initial amount \(I\)):

From the first week: \[ I + 12 = 112 \] So, we solve for \(I\): \[ I = 112 - 12 = 100 \]

Now that we have determined that Brittany opened her bank account with $100 and added $12 each week, the correct answer is:

C: Brittany opened the account with $100 and added $12 each week.