There is a mistake in the sentence.Find the mistake and correct it

I.There is a mistake in the sentence.Find the mistake and correct it.

1. Tim is at the same age as Hoa
2. At recess, the students practice to play basketball 
3. Do you know how much a banana cost?
4. The teacher says Ba will be a famous artist in one day 
5. Some students are playing games as blind man's buff and catch
6. There are less TV programs for teenagers than there are for adults 
 7. People are living longer so there are more many old people
GIÚP MK VỚI MN ƠI!!!!!!!!!!!!!!!!!!!!!!(ai làm được,đúng và giải thích hết tất cả các câu trên thì mk sẽ tặng xu cho người đó)