1) balls in total. So the probability of getting all different colours would be:
a) You require the last digit to be even. So the probability is .
b) You require the last digit to be odd. So the probability is .
c) You require the first digit to be a 0, 1, 2, 3. So the probability is .
d) There are different combinations of 4 numbers from the 8 given.
It has to be greater than 3000 and less than 4000. This means you know the first digit has to be a 3 and there are 7 digits left to choose from.
That means you will be finding the number of combinations of 3 digits from the 7 remaining.
There are combinations.
That means the probability of having a number less than 4000 and greater than 3000 is .