She first gave away half of her 20 brownies, or 20/2=<<20/2=10>>10 brownies, to the faculty.
The remaining brownies number 20-10=<<20-10=10>>10 brownies.
She gave half of these remaining brownies, or 10/2=<<10/2=5>>5 brownies, to Carl.
This reduced her number from 10 down to 10-5=<<10-5=5>>5 brownies.
Finally, she gave away another 2, leaving her with 5-2=<<5-2=3>>3 brownies.
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