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 0.225;
(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.





Scores
1
2
3
4
5
6


Frequency
25
30
x
28
40
32
