Which expression can be used to convert 22 Australian dollars to US dollars?

Assume 1.2 Australian dollars equals 1 US dollar.

A. [tex]\$ 22 \text{ AUD} \times \frac{1.2 \text{ USD}}{1 \text{ AUD}}[/tex]

B. [tex]\$ 22 \text{ AUD} \times \frac{1 \text{ USD}}{1.2 \text{ AUD}}[/tex]

C. [tex]\$ 1.20 \text{ AUD} \times \frac{1 \text{ USD}}{1.2 \text{ AUD}}[/tex]

D. [tex]\$ 1.20 \text{ AUD} \times \frac{1.2 \text{ USD}}{1 \text{ AUD}}[/tex]



Answer :

Let's determine which expression correctly converts 22 Australian dollars (AUD) to US dollars (USD) given the exchange rate of 1.2 AUD per 1 USD.

Given the information:
- 1.2 AUD = 1 USD

To convert from AUD to USD, we need to use the reciprocal of the exchange rate:

1 USD is equivalent to 1/1.2 AUD.

Thus, the expression should invert the ratio to move from AUD to USD.

Now, looking at the options:

1. [tex]\(\$ 22 \text{ AUD} \times \frac{1.2 \text{ USD}}{1 \text{ AUD}}\)[/tex]

This option uses the exchange rate directly but it's set up to convert from USD to AUD, not from AUD to USD.

2. [tex]\(\$ 22 \text{ AUD} \times \frac{1 \text{ USD}}{1.2 \text{ AUD}}\)[/tex]

This option correctly inverts the rate to convert AUD to USD.

3. [tex]\(\$ 1.20 \text{ AUD} \times \frac{1 \text{ USD}}{1.2 \text{ AUD}}\)[/tex]

This option incorrectly uses [tex]\(1.20 \text{ AUD}\)[/tex] instead of [tex]\(22 \text{ AUD}\)[/tex] and should not be considered for conversion of 22 AUD.

4. [tex]\(\$ 1.20 \text{ AUD} \times \frac{1.2 \text{ USD}}{1 \text{ AUD}}\)[/tex]

This option also incorrectly starts with 1.20 AUD and uses the ratio incorrectly for converting AUD to USD.

The correct expression to use for converting 22 AUD to USD is:

[tex]\[ \$ 22 \text{ AUD} \times \frac{1 \text{ USD}}{1.2 \text{ AUD}} \][/tex]

Applying this expression:

[tex]\[ \$ 22 \text{ AUD} \times \frac{1 \text{ USD}}{1.2 \text{ AUD}} = \$ 18.333\ldots \text{ USD} \][/tex]

Therefore, the appropriate expression to convert 22 AUD to USD is: [tex]\( \$22 \text{ AUD} \times \frac{1 \text{ USD}}{1.2 \text{ AUD}} \)[/tex].