Any help with this question also please?

Diffie$-$Hellman key exchange $($related to ECC$)$ is a mathematical method of securely exchanging

cryptographic keys over a public channel and was one of the first public$-$key protocols. It is used to

secure a variety of Internet services. Suppose Alice and Bob wants to exchange data across the

internet. They will choose prime value $q=19$ and primitive root $=11.$ If Alice's secret key is $10$ and

Bob's secret key is $20,$ calculate:

a$)$ Public key of Alice

b$)$ Public key of Bob

c$)$ Shared key $($private key of Alice and Bob$)$