Calculate the probability of obtaining obtaining on rolling a fair dice: a) an even number, b) a number greater than 2, c) an odd number, d) a number divisible by 3?

1 Answer
Apr 19, 2016

#a#) #1/2#
#b#) #2/3#
#c#) #1/2#
#d#) #1/3#

Explanation:

The probability of an event occurring given a discrete number of possibilities is given by #"number of ways the event can occur"/"number of total possibilities"#

Given the roll of a single die, there are #6# total possibilities (a roll of #1, 2, 3, 4, 5#, or #6#).

#a)# As there are #3# possible even numbers which can be obtained by rolling a die (#2, 4#, or #6#), the probability of rolling an even number is #3/6 = 1/2#

#b)# As there are #4# possible numbers greater than #2# (#3, 4, 5#, or #6#), the probability is #4/6 = 2/3#

#c)# As there are #3# possible odd numbers (#1, 3#, or #5#), the probability is #3/6 = 1/2#

#d)# As there are #2# possible numbers which are divisible by #3# (#3# or #6#), the probability is #2/6 = 1/3#