A die is tossed until the sum of the rolls is 15 or greater.

What is the most likely total? What is the the least likely total which can occur?

I would say the least likely total is definitely 20 as the only way that can happen is if the sum so far was 14 and then you rolled a 20.

The ways of getting 15 or over are:

Alredy on... ---------- Rolled---Totals
9-------------------------6-------15
10---------------------5 or 6-----15 and 16
11-------------------4,5 or 6-----15,16 and 17
12-----------------3,4,5 or 6-----15,16,17 and 18
etc.

As you can see the number that comes up every time is 15, so I think 15 would be the most common.

Posted by Lewis on 2003-07-24 09:15:11