00:01
Okay, one method here is draw a venn diagram on the left here in blue sets a, b and c and u the entire set and just fill in the numbers start in the middle here.
00:14
Well, there is no number in both a, b and c.
00:18
So that's empty let's do now where a and b overlap and we can see 1, 3, 5 occurs in both a and in b so that means here is 1, 3 and 5 then look at a and c we have 1, 2, 3, 4, 5, 4 and 6 clearly 4 is the same in both sets so that means 4 has to go here and then a is 1, 2, 3, 4, 5 so 2 must go there.
01:01
B is 1, 3, 5.
01:02
So this and this are blank and c is 4 and 6 now outside we have 0 1, 2, 3, 4, 5, 6 are covered.
01:17
That means we need 7, 8, 9 and 10 that's my venn diagram now to work out a, u and b, the first one just combine the two sets a u and b is simply this area here that i shaded.
01:42
So in fact that will be just set a so 1, 2, 3, 4 and 5 is a u and b a and b combined together now part b was a u and c let's combine set a with set c.
02:08
In other words all on this area here i shaded.
02:13
So all of a plus 6 so that will be 1, 2, 3, 4, 5 and 6 then part c is where a and b or hang on where a and c intersect.
02:37
So a and c is the overlap between a and c that occurs here.
02:44
That's where a and c overlap number 4...