00:01
Okay then the quiz is multiple choice.
00:02
I give you four answers.
00:04
Multiple choice, then you see.
00:06
Which means the chance you are correct if you are guessing is one chance out of four.
00:17
Which implies the of your wrong and not correct is one minus a quarter, so three quarters.
00:26
If you're correct, one chance in four, incorrect, three out of four.
00:30
What i want is for 10 questions exactly two correct.
00:35
So that's one quarter has to occur twice, so one quarter squared.
00:41
This implies wrong eight times.
00:44
So three quarters, power of eight, the 10 questions.
00:49
Those two questions could be first and second, fourth and ninth.
00:54
There are more ways than one to get exactly two correct.
00:57
And it's a binomial experiment here basically, so we can use the binomial method...