In rural areas, relays play a critical role in extending internet coverage. Each relay receives messages from a base station and transmits them to a user at each time slot. Also, it relays messages from users back to the base station. Collision may occur if both user and base station transmit messages to the relay at the same time. The network is idle 40% of the time, meaning that neither base nor users have messages to send. Assuming that 20% of the time a user has messages to transmit and 50% of the time the base station has messages to transmit, determine the probability of collision.