Q5. How many backpacks do you own, and how much did they each cost?

I got two backpacks.

I don't remember their cost how much they cost[또는 their price] exactly.

They cost less than 30 dollars each.

Q6. What do you use backpacks for?

I usually carry my wallet, iPad and several belongings in my backpack.

Q7. What are the qualities of a good backpack?

Most of all, it needs to hold a lot of stuff because I have many belongings to carry around in general.

Secondly, durability is important as well.

And if it's light? the best.

Q5. How many backpacks do you own, and how much did they each cost?

I got two backpacks.

I don't remember their cost how much they cost[또는 their price] exactly.

They cost less than 30 dollars each.

Q6. What do you use backpacks for?

I usually carry my wallet, iPad and several belongings in my backpack.

Q7. What are the qualities of a good backpack?

Most of all, it needs to hold a lot of stuff because I have many belongings to carry around in general.

Secondly, durability is important as well.

And if it's light? the best.

-> 잘하셨습니다. 수정할 부분이 별로 없네요!