1 A die is rolled three times. Find the probability that the sum of the outcomes
is
(a) greater than 9.
(b) an odd number.
a
total.way = 6*6*6
count.greater.than.nine = 0
for (i in c(1:6)) {
for (j in c(1:6)) {
for (k in c(1:6)) {
if (i+j+k > 9) {
count.greater.than.nine = count.greater.than.nine + 1
}
}
}
}
(count.greater.than.nine)
## [1] 135
(probability = count.greater.than.nine/total.way)
## [1] 0.625
b
total.way = 6*6*6
count.odd.number = 0
for (i in c(1:6)) {
for (j in c(1:6)) {
for (k in c(1:6)) {
if ((i+j+k) %% 2 != 0) {
count.odd.number = count.odd.number + 1
}
}
}
}
(count.odd.number)
## [1] 108
(probability = count.odd.number/total.way)
## [1] 0.5