To solve this problem, we'll calculate the interest earned from each account separately and then determine the overall percentage interest for the total amount deposited.

Part (a): What was the total interest earned at the end of 1 year?

1. Calculate the interest earned from the $7000 deposited at 3% interest:

   $\text{Interest} = 7000 \times \frac{3}{100} = 210 \, \text{dollars}$

2. Calculate the interest earned from the $9000 deposited at 11% interest:

   $\text{Interest} = 9000 \times \frac{11}{100} = 990 \, \text{dollars}$

3. Add the interest from both accounts to get the total interest earned:

   $\text{Total interest} = 210 \, \text{dollars} + 990 \, \text{dollars} = 1200 \, \text{dollars}$

Part (b): What was the percent interest for the total deposited?

1. Calculate the total amount deposited:

   $\text{Total deposited} = 7000 + 9000 = 16000 \, \text{dollars}$

2. Calculate the percent interest based on the total interest earned:

   $\text{Percent interest} = \left(\frac{1200 \, \text{dollars}}{16000 \, \text{dollars}}\right) \times 100 = 7.5\%$

Final Answers:

• (a) The total interest earned at the end of 1 year was $1200.
• (b) The percent interest for the total deposited was 7.5%.

Do you want details or have any questions?

Here are 5 related questions for further practice:

1. If Ann had deposited $8000 at 3% interest and $8000 at 11% interest, what would the total interest earned be?
2. How much would Ann earn if she reinvested the $1200 interest into the 11% account for another year?
3. If the interest rates were swapped between the two accounts, how much interest would Ann have earned?
4. What would the total interest be if both accounts paid the same interest rate of 7.5%?
5. How much would Ann need to deposit into a 5% interest account to earn $1200 in one year?

Tip: When dealing with different interest rates, always calculate the interest for each investment separately before combining them for the total.