Question

A 12-sided solid has faces numbered 1 through 12

a. Find the probability of rolling a number greater than 5.
s. If the 12-sided solid is rolled 180 times, how many times
would you expect either a 3,9, or 11 to be rolled?

Answer 1

a) 7/12

b) 1/6

Explanation:

(1)

Number greater than 5 include;

6, 7, 8, 9,10, 11, & 12

= 7

Prbabilyt of event = number of outcome / total number of possible events

= 7/ 12

(2)

Total number of possible events = 180 * 12

= 2160

Number of outcomes for;

Rolling a 3 = 1 * 120 / 2160 = 120/2160

Rolling a 9 = 1 * 120/2160 = 120/2160

Rolling a 11 = 1 * 120/2160 = 120/2160

Since we are using the OR rule, well add the possibilities

120/2160 * 3

360/2160

= 1/6