Is $-(NH-CHR-CO)_n-$ a homopolymer or a copolymer?

Which of the following is a biodegradable polymer?

$A$ polymer contains $50$ molecules with molecular mass $5,000$,$100$ molecules with molecular mass $10,000$ and $50$ molecules with molecular mass $15,000$. Calculate the number average molecular mass. (in $,000$)

Which of the following is a polyamide?

Identify the set with only addition homopolymers.

Which among the following polymers belongs to the class of thermoplastic polymers?