Answer:
For each question we have 4 choices. So if you have 10 on such questions, you ll have :
4*4*4*4*4*4*4*4*4*4= 4^10 = 2048
Getting 8 correct means=> 8 corrects and two wrongs
3/4 is the probability if a question is answered wrong
1/4 is the probability if a question is answered correctly
so we can consider this probability :
P=(3/4)*(3/4)*(1/4)*(1/4)*(1/4)*(1/4)*(1/4)*(1/4)*(1/4)*(1/4)
=> P=0.00000858306
But as we can select any combination of 2 from 10 for being wrong, so we need to multiply P by (10,2)=10!/(2!*8!) =45
so the answer is P*45 = 0.00038623809
So not very lucky to answer randomly!
By the way, is it a question from your home work assignment? ;) ;
tbh google
