Which expressions are polynomials?

Can someone please check my work?

A23 – year – old male buys 100/300/100 liability insurance, collision insurance with a $100 deductible, and comprehensive insurance with a $250 deductible? what is his total annual premium? (a) $1142.00 (b) $1765.45 (c) $1770.10 (d) $1785.25

Can someone tell me if these are correct?

Kate has 50 quarters and dimes. she has a total of $9.80. how many dimes that she have?