Scores 1 2 3 4 5 6 Frequency 25 30 x 28 40 32 The table shows the outcome when a die is thrown a number of times. If the probability of obtaining a 3 is 0.2...

The table shows the outcome when a die is thrown a number of times. If the probability of obtaining a 3 is 0.225;

(a) How many times was the die thrown?

(b) Calculate the probability that a trial chosen at random gives a score of an even number or a prime number.