Kendra’s savings account has a balance of −$70 . She puts $50 each week into her account. After a certain period of time, she has $330 in her account.

Question

At this rate, how many weeks did it take Kendra to save $330?

Answer 1

To solve the problem, we start with Kendra's initial balance and the amount she adds each week, and then determine how long it takes to reach her target balance.

1. Initial Balance: Kendra's savings account starts at -$70.
2. Weekly Contribution: Kendra adds $50 each week.
3. Target Balance: Kendra wants to reach a balance of $330.

We can set up the following equation to represent her balance after \( w \) weeks:

\[ \text{Balance after } w \text{ weeks} = \text{Initial Balance} + (\text{Weekly Contribution} \times w) \]

Substituting in her values:

\[ \text{Balance after } w \text{ weeks} = -70 + 50w \]

We want this to equal $330:

\[ -70 + 50w = 330 \]

Now, we solve for \( w \):

1. Add 70 to both sides:

\[ 50w = 330 + 70 \]

\[ 50w = 400 \]

2. Divide both sides by 50:

\[ w = \frac{400}{50} \]

\[ w = 8 \]

So, it took Kendra 8 weeks to save $330 in her account.