00:01
So the way to figure out this problem is just to kind of create three venn diagrams.
00:06
Okay.
00:06
So i have students taking math, taking english and taking history.
00:10
And i'm trying to find all these different lines, including the students outside.
00:14
So let's start with the intersection.
00:17
Five are taking all three subjects.
00:20
10 are taking history and math.
00:22
Okay.
00:22
So the overlap of history and math will add to 10.
00:26
So there's five overall, and then that must be there's five only taking history and math.
00:32
Ten are taking english and history.
00:34
So english and history will overlap and create 10.
00:37
So these two must add to 10.
00:38
So this number here must be five.
00:40
And then 15 are taking english and math.
00:44
Okay.
00:44
So these two overlap to create 15.
00:46
That means these two numbers add to 15.
00:48
So this will be 10.
00:50
Okay...