As of 1st January 2021 an investor owns 2,000 shares of Corp A. These shares have a cost base of $24,000. During 2021 the investor had the following transactions of Corp A shares:

3/1/2021 sold 1,000 shares for $15,000

4/1/2021 sold 1,000 shares for $10,000

4/20/2021 bought 1,000 shares for $11,000

(a) What was the capital gain or loss for 2021?

(b) What is the adjusted cost base of the investor's shares of Corp A at the end of 2021?