$2)$ An investor has a promissory note for $$9,000$ that matures $300$ days from purchase at $4\mathrm{.}5\%$

simple interest. After $138$ days, they sell it to a bank which discounts promissory notes at $3\mathrm{.}5\%$

interest. $5$ points

a$)$ How much does the bank pay for the prom note?

b$)$ What rate of return does the investor achieve?