Hey there! Hello!
For these problems, you'll need to know that there are 16 oz in 1 lb, which I'm sure you already know, given that you've already answered number seven.
The simplest way I can think to do it is divide the number of oz given (in the case of number eight, it's 50 oz) by 16, since that will give you the number of pounds you're looking for.
For number eight, you have an improper fraction of 50/16. In order to turn an improper fraction into a mixed number, you'll have to use long division and divide 50 by 16. If you write this long division problem out, you can see that 16 goes into 50 three times, and there will be a remainder of 2. 3 is your whole number, and 2 will go over 50. Your final mixed number will be 3 2/50.
If you follow the same steps for number nine, you'll get a mixed number of 2 12/50.
I encourage you to try the rest on your own, let me know if you need any additional help! :-)