Math
posted by Neid on .
Mack rolls a 15sided cube 45 times, what would you predict the probability to be of Mack's rolling a number less than 5?

The concept of a 15 sided cube startles me.
Did you make this question up yourself? 
No, it's a question on a 7th grade Skills Review

You are right; there's no way a 15sided die could be fair. Even if the area of each face is the same, the angles cannot all be equal, since there is no regular 15hedron.

Perhaps they want us to assume it is possible.
4 out of the 15 sides are less than 5
so
about 4/15 in each roll
so in each roll the probability of NOT getting less than 5 is 11/15
so the probability of NEVER getting less than 5 is (11/15)^45
so our answer is
1  (11/15)^45
which is about
1  8.7^7
which is so close to one that you can count on it :)