Probability Questions

There are $8$ different symbols. A code is formed by selecting $5$ symbols such that each symbol can be used only once (that is, no symbol is repeated in the code). Also, the order of symbols matters. How many different codes can be formed?

A coin is flipped two times. What is the probability of getting at least one head?

The probability of an event happening is $0.55$. What is the probability that the event does not happen?

A number is selected at random from $100$ to $199$. What is the probability that the number is divisible by $2$ and has exactly two even digits?

A number is chosen at random from $1$ to $200$. What is the probability that it is a perfect square or a multiple of $6$?