I've written about writing scams before. They're very common online, and offline too. If you're a new writer, PLEASE do not write "tests". Or "scope" a project.
Companies (and sometimes individuals) know how naive, insecure and needy many writers are. They love having their work done for FREE. Here's a very common tale of woe from WritersWeekly:
I found a freelance copyediting position (online). I emailed them expressing interest and with some questions about the company and they emailed me back with a sample chapter to edit.If anyone, at any time, asks you to write something for them for free, just delete the email, or if you find the gig online, breeze right on by. No matter how plausible these "jobs" sound, they're not.
A legitimate company, if they're not sure that you can handle the work will PAY you to do some trial work - in ADVANCE.
Never, ever take any so-called tests. If you have writing credits, they're enough to give you credibility. If you have no writing credits, write some sample articles.
Again, please - never, ever take writing tests, write trials, or write scopes. Write some samples, if you have no credits, create a Web site, and get legitimate writing gigs. Currently, businesses are DESPERATE for writers, and they pay real money. Don't get taken in.