Explain diffie-helman protocol for sending message

1. Alice has selected the public key (n = 33; e = 3). Using this key, Bob sends plaintext X to Alice which encrypts as ciphertext 10. What is the plaintext X?

2. In the Diffie-Helman protocol, the common modulus is chosen as n = 19 and the generator g is chosen to be 2. Alice and Bob choose the numbers 6 and 10 privately. What will be the public values they transmit and what would be the final secret computed?”