If you are asking if she wrote half her paper:
Add the portions she has written.
= 2/10 + 1/10 + 1/10
= 4/10
simplify by 2
= 2/5 (or 0.4) has been written
2/5 < 1/2
0.4 < 0.5
ANSWER: She is not correct. She has not written 1/2 of her paper because 2/5 (or 0.4) is less than 1/2 (or 0.5).
Hope this helps! :)