nmr help chemistry

1a) C next to C=O, 20-50 ppm according to the table C of the data sheet
https://filestore.aqa.org.uk/resources/chemistry/AQA-7405-SDB.PDF

3c) It is esterification which is a condensation reaction. It is a nucleophilic addition-elimination reaction. Addition occurs first then elimination so addition-elimination. The nature of the attacking species is nucleophile so nucleophilic addition elimination
https://www.chemguide.co.uk/organicprops/anhydrides/oxygen.html

3d) Similar to reaction with water, instead of H-O-H you have H-O-CH3. So you have the C-O bond breaking, then you get COOH and COOCH3 groups

https://imgur.com/a/uTz3x79
i showed C in the same environment by same number
total is 12

Your reasoning for 10 peaks is unclear.

Hi, thanks for the reply. For 3d I am still unclear on. What would the reaction with h2o be in the first place? Also, for the question countin the number of carbon environments, surely the two benzene rings on the "right hand side" are both in exactly the same environment. Like when there are two methyl groups attached to the same c in a molecule, both carbons are in the same environment in some cases. Therefore i'm struggling to understand why we count the number of carbon environments in both of these "benzene rings" and adding them together instead of just using one?