You answered 8 tasks out of 10 correctly.
That's 80%.

Your results:
1) He played handball. - He he did not pay handball. Correct answer: He played handball. - He did not play handball.
2) Susan waited in the kitchen. - Susan did not wait in the kitchen.
3) I made the beds. - I did not make the beds.
4) They cleaned the classroom. - They did not clean the classroom.
5) She asked a lot of questions. - She did not ask a lot of questions.
6) The friends got new computers. - The friends did not get new computers.
7) I was in Sofia last weekend. - I was not in Sofia last weekend.
8) You built a house. - You did not build a house.
9) Christian bought a new guitar. - Christian did not boy a new guitar. Correct answer: Christian bought a new guitar. - Christian did not buy a new guitar.
10) We went shopping. - We did not wet shopping.