### Mathematical Literacy Grade 11
### Mopani East District
### Assignment 2 (Task 5)

#### 1.2
Mr. Mokhethi invested R10,000 at another bank at an interest rate of 7.5% compounded annually. Determine the value of the investment after 2 years.
[tex]\[
(6)
\][/tex]

#### 1.3
Below is the list of groceries with the average prices for each item in 2022 and in 2023.
[tex]\[
\begin{tabular}{|l|c|c|c|}
\hline
Item & Price 2022 & Price 2023 & \% Change \\
\hline
Bread (loaf) & R 17.00 & R 19.50 & A \\
\hline
Milk (D) & R 16.49 & B & 14\% \\
\hline
Wild Island (juice) & C & R 16.99 & 5\% \\
\hline
Chicken (2kg) & R 55.00 & R 72.50 & D \\
\hline
\end{tabular}
\][/tex]
[tex]\[ [Adapted\ from\ www.pricecheck.co.za] \][/tex]

#### 1.3.1
Define the term inflation.

#### 1.3.2
Determine the price of milk in 2023 if the average inflation rate was 14%. Round off your answer to two decimal places.

#### 1.3.3
Calculate the percentage change of bread.

#### 1.3.4
Explain what it means if the inflation rate is 5.3%.

#### 1.3.5
Calculate the price of the juice (Wild Island) in 2022 if it has increased by 5%.



Answer :

Let's tackle each part of the assignment step-by-step.

### 1.2 Mr. Mokhethi's Investment

Mr. Mokhethi invested R10,000 at an interest rate of 7.5% compounded annually. To find the value of the investment after 2 years, we use the compound interest formula:

[tex]\[ A = P \left(1 + \frac{r}{n}\right)^{nt} \][/tex]

Where:
- [tex]\( A \)[/tex] is the amount of money accumulated after n years, including interest.
- [tex]\( P \)[/tex] is the principal amount (the initial amount of money).
- [tex]\( r \)[/tex] is the annual interest rate (decimal).
- [tex]\( n \)[/tex] is the number of times that interest is compounded per year.
- [tex]\( t \)[/tex] is the time the money is invested for in years.

In this case:
- [tex]\( P = 10,000 \)[/tex]
- [tex]\( r = 7.5\% = 0.075 \)[/tex]
- [tex]\( n = 1 \)[/tex] (compounded annually)
- [tex]\( t = 2 \)[/tex] years

Plug these values into the formula:

[tex]\[ A = 10,000 \left(1 + \frac{0.075}{1}\right)^{1 \cdot 2} \][/tex]
[tex]\[ A = 10,000 \left(1 + 0.075\right)^2 \][/tex]
[tex]\[ A = 10,000 \left(1.075\right)^2 \][/tex]
[tex]\[ A = 10,000 \left(1.155625\right) \][/tex]
[tex]\[ A = 11,556.25 \][/tex]

So, the value of the investment after 2 years is R11,556.25.

### 1.3.1 Definition of Inflation

Inflation is the rate at which the general level of prices for goods and services is rising and subsequently eroding the purchasing power of currency. It indicates how much more expensive a set of goods and services has become over a certain period, usually a year.

### 1.3.2 Price of Milk in 2023

Given that the price of milk in 2022 was R16.49 and the average inflation rate was 14%, we calculate the price in 2023 using the formula for calculating price increase due to inflation:

[tex]\[ \text{New Price} = \text{Old Price} \times (1 + \text{Inflation Rate}) \][/tex]

Here:
- Old Price = 16.49
- Inflation Rate = 14% = 0.14

[tex]\[ \text{New Price} = 16.49 \times (1 + 0.14) \][/tex]
[tex]\[ \text{New Price} = 16.49 \times 1.14 \][/tex]
[tex]\[ \text{New Price} = 18.8 \][/tex]

Thus, the price of milk in 2023 is R18.80.

### 1.3.3 Percentage Change of Bread

To calculate the percentage change in the price of bread from 2022 to 2023, use the formula for percentage change:

[tex]\[ \text{Percentage Change} = \left(\frac{\text{New Price} - \text{Old Price}}{\text{Old Price}}\right) \times 100 \% \][/tex]

Here:
- Old Price = 17.00
- New Price = 19.50

[tex]\[ \text{Percentage Change} = \left(\frac{19.50 - 17.00}{17.00}\right) \times 100 \% \][/tex]
[tex]\[ \text{Percentage Change} = \left(\frac{2.50}{17.00}\right) \times 100 \% \][/tex]
[tex]\[ \text{Percentage Change} = 0.1470588235 \times 100 \% \][/tex]
[tex]\[ \text{Percentage Change} = 14.71 \% \][/tex]

Thus, the percentage change in the price of bread is approximately 14.71%.

### 1.3.4 Explanation of 5.3% Inflation Rate

An inflation rate of 5.3% means that, on average, prices for goods and services have increased by 5.3% over a specified period, usually one year. This implies that items that may have cost 100 currency units in the previous year would now cost 105.3 currency units.

### 1.3.5 Price of Wild Island Juice in 2022

Given that the price of Wild Island juice in 2023 is R16.99 and it increased by 5%, we calculate the 2022 price using the formula:

[tex]\[ \text{Old Price} = \frac{\text{New Price}}{1 + \text{Inflation Rate}} \][/tex]

Here:
- New Price = 16.99
- Inflation Rate = 5% = 0.05

[tex]\[ \text{Old Price} = \frac{16.99}{1 + 0.05} \][/tex]
[tex]\[ \text{Old Price} = \frac{16.99}{1.05} \][/tex]
[tex]\[ \text{Old Price} = 16.18 \][/tex]

Thus, the price of Wild Island juice in 2022 was approximately R16.18.