Marcus invested his savings in shares of a new company. The company's share price dropped by $0.75 at the end of the first year, and by a further $2.00 at the end of the second year.

The share price was $18.87 at the end of the second year.

a. Calculate the original share price (at the beginning of the first year). Round to the nearest cent.

b. Calculate the percent change in the share price over the two-year period. Round to two decimal places.