1. What is the difference between RELATIVE FREQUENCY and PROBABILITY.

Relative frequencies are usually obtained from experiments such as throwing a die 100 times, whereas probabilities are calculated from theory e.g Knowing that a six-sided die will have a one sixth probability of getting any of the 6 numbers.

2. What is the difference between an experiment and a trial?

An experiment could be rolling a die 10 times, whereas each of the 10 rolls would be a trial.

3. Can a probability be greater than 1?

No. The highest possible probability is 1.
An event with a probability of 1 is certain to happen.