Simple interest and compound interest are two methods of appreciation. Under which method will investments appreciate faster?

Compound interest leads to faster appreciation because the interest earned in each period is added to the principal, and subsequent interest is calculated on this larger amount. This creates an accelerating growth effect.

The formula for simple interest is $A = P(1 + i \cdot n)$.
Given: $A = R22\,464$, $i = 5.5\% = 0.055$, $n = 8$ years.
We need to find $P$.

The initial investment was $\boxed{\text{R15 600}}$.

The formula for compound interest compounded quarterly is $A = P(1 + \frac{i}{m})^{n \cdot m}$.
Given: $P = R17\,500$, $i = 7.5\% = 0.075$, $n = 12$ years, $m = 4$ (quarterly).

The amount of her investment after 12 years is $\boxed{\text{R42 886.53}}$.

The interest earned is the final amount minus the initial principal.

The interest her investment would earn is $\boxed{\text{R25 386.53}}$.

First, calculate the depreciated value of the old car. The formula for reducing balance depreciation is $A = P(1 - i)^n$.
Given: $P = R350\,000$, $i = 20\% = 0.20$, $n = 7$ years.

Next, calculate the appreciated value of the new car. The formula for simple interest appreciation is $A = P(1 + i \cdot n)$.
Given: $P = R350\,000$, $i = 5\% = 0.05$, $n = 7$ years.

Finally, calculate the amount Musi will pay.

Musi will pay $\boxed{\text{R399 099.68}}$.

Taxable income is the portion of an individual's or company's gross income that is subject to income tax. It is calculated by subtracting allowable deductions from gross income.

A tax rebate is an amount by which a taxpayer's tax liability is reduced. It directly lowers the amount of tax owed, rather than reducing the taxable income.

First, calculate Mary's total annual gross income.

This is Mary's taxable income, assuming no other deductions.
To calculate Mary's actual tax liability and determine if she overpaid or underpaid, the individual tax rate table for the financial year 2024 from SARS is required. This table is not provided in the image. Without the tax brackets, rates, and applicable rebates for a 70-year-old, the final tax calculation cannot be completed.

Her total annual taxable income is $\boxed{\text{R1 975 000}}$.