+0  
 
0
37
2
avatar

We flip a fair coin 10 times. What is the probability that we get heads in at least 8 of the 10 flips?

 Nov 2, 2020
 #1
avatar
0

10!/[8!*2!*2^10] + 10!/[9!*1!*2^10] + [10!/[10!*0!*2^10] ==[45 + 10 + 1] / 2^10==56 / 2^10==7 / 128

 Nov 2, 2020
 #2
avatar
0

You can also verify it this way:

 

(10 nCr 8+10 nCr 9+10 nCr 10)/2^10= 7 / 128

 Nov 2, 2020

15 Online Users

avatar
avatar