MINNEAPOLIS (WCCO) — Every Friday, Heather Brown takes a look at some of the best Good Questions submitted by viewers the previous week. This Friday, she’s looking at filing fees on taxes, the size of water bottles and USPS trucks on Sunday.

Joe had to pay $19.99 to e-file his taxes. He wants to know why it’s not free.

Taxpayers can’t e-file directly with the IRS or Minnesota Department of Revenue, so they must e-file through a company that provides the proper online software. People pay the fee to that company, and the government doesn’t see any of that money.

In a statement, the Minnesota Department of Revenue says, “[It] is not affiliated with any software companies and we do not endorse any products.”

Here is a list of companies that offer free electronic filing, if you qualify. Volunteer Income Tax Assistance (VITA) sites can also help taxpayers e-file with no fee under certain conditions.

Paul from Burnsville asks: “Why do we see postal trucks in the neighborhood on Sundays?”

There’s a good chance those trucks are delivering packages from Amazon, according to the U.S. Postal Service. In 2014, the online retailer and USPS entered into an agreement to deliver packages on Sundays. That deal recently expanded into the Minneapolis-St. Paul metro area. In December, USPS also delivered holiday packages from all shippers on Sundays.

Lynn from Oakdale wants to know: “Why are water bottles 16.9 ounces?”

That amount equals 500 milliliters (or one-half liter). Given the water bottle companies don’t just sell in the U.S., they use the metric system, which is the international standard.

Heather Brown