I have a special 6-sided dice such that
The probability of rolling a 2 is twice the probability of rolling a 1,
the probability of rolling a 3 is thrice the probability of rolling a 1,
the probability of rolling a 4 is quadruple the probability of rolling a 1,
the probability of rolling a 5 is quintuple the probability of rolling a 1, and
the probability of rolling a 6 is hextuple the probability of rolling a 1.
What is the probability of rolling an even number?
Guest Jul 4, 2021
k = probability of rolling a 1
k + 2k + 3k + 4k + 5k + 6k = 1
21k = 1
k = 1/21
probability of rolling an even number = 2/21 + 4/21 + 6/21 = 12/21 = 4/7