Tonya mailed her brother a postcard from Australia

To determine how long it would take for the postcard to reach Tonya's brother, we need to consider the mailing process and the distance between Australia and her brother's location. Here's how you can estimate the timeframe:

Step 1: Determine the distance:
Find out the location of Tonya's brother. If you know the specific city or country, it will help in calculating the distance accurately. Let's assume her brother is in the United States.

Step 2: Calculate the mailing time:
The average mailing time for international postcards can vary depending on several factors, such as the efficiency of postal services, customs clearance procedures, and transport options. The quickest method is typically using an express mail service, but it can also be more expensive.

Step 3: Estimate the time frame:
To get a rough estimate, you can consider the average time it takes for mail to travel from Australia to the United States. This can vary but is generally around 7-10 business days for regular mail. Express shipping can reduce the time frame to 3-5 business days.

Keep in mind that the mailing time may be affected by factors such as public holidays, delays in the postal system, and any transportation disruptions.

Therefore, based on the assumptions made, it can take anywhere between 7-10 business days for regular mail and 3-5 business days for express mail to deliver the postcard from Australia to the United States.