00:01
Okay, we have two dice here, one red, one green.
00:04
We are told event a is the red dice showing a 1, and the event b, the sum of the two dice is 4.
00:12
And i want to work out an expression first for red shows 1 and the sum is 4.
00:20
Well, this symbol here is a symbol for and.
00:28
This one here is a symbol for or.
00:32
So what i want is a and b.
00:36
So just write down a and b and that's the first one.
00:44
Now i want to work out a number of elements in this particular set.
00:49
Well if you throw two dice then the lowest score you can get is 2.
00:54
It will be a 1 on the red and a 1 on the green...