<p>I know that it is possible to change subject tests on the test date, but is it also possibe to add a subject test. If so, then how much extra would it cost?</p>
<p>yes...just take the third test and you will be billed later.</p>
<p>Yes, it is possible. How much it costs depends on the test, they'll bill you for the additional charge.</p>
<p>sweet,</p>
<p>thank you so much.</p>