Question

28 mike put $1000 into a simple interest account for a year.
he did not take any money out or add any money to the account.
at the end of the year he had $1050 in the account.
what was the annual percentage interest rate?

29 seth draws a target as shown.
what is the area of the entire target?
round your answer to the nearest square centimetre.

Explanation:

Question 28: Calculate the interest earned

Using the Percentage Calculations knowledge point

$$
LATEXBLOCK0
$$

Question 28: Calculate the annual interest rate

Using the Percentage Calculations knowledge point

$$
LATEXBLOCK1
$$

Question 29: Find the radius of the entire target

To find the area of the entire target, we first need to determine its total radius. The target consists of concentric regions. Looking at the diagram, the innermost circle has a radius of \(2.5\text{ cm}\). Each subsequent ring adds another \(2.5\text{ cm}\) to the radius.
Using the Geometric Formulas knowledge point, we count the total number of concentric sections from the center to the outermost boundary:

• Innermost circle: \(2.5\text{ cm}\)
• Second ring: \(+2.5\text{ cm}\)
• Third ring: \(+2.5\text{ cm}\)
• Outermost ring: \(+2.5\text{ cm}\)

There are 4 segments of \(2.5\text{ cm}\) each:

$$ R = 2.5 + 2.5 + 2.5 + 2.5 = 10\text{ cm} $$

Question 29: Calculate the area of the entire target

Now we calculate the area of a circle with radius \(R = 10\text{ cm}\).
Using the Geometric Formulas knowledge point, the area formula is:

$$ \text{Area} = \pi R^2 $$

Substituting our radius:

$$ \text{Area} = \pi \times 10^2 = 100\pi \approx 314.159\text{ cm}^2 $$

Question 29: Round to the nearest square centimetre

We round the calculated area to the nearest whole number:

$$ \text{Area} \approx 314\text{ cm}^2 $$

Answer:

Question 28

<blank>5</blank> %

Question 29

<blank>314</blank> \(\text{cm}^2\)