Answer:
B
Step-by-step explanation:
Answer:
21
Step-by-step explanation:
25-4=21
All of the questions are 25, he hasn't answered 4, so fron 25 you remove 4, and the answer is 21.
105/2^9
Step-by-step explanation:
The probability of getting a head in a single toss
p=12
The probability of not getting a head in a single toss
q=1−12=12
Now, using Binomial theorem of probability,
The probability of getting exactly r=4 heads in total n=10 tosses
=10C4(1/2)4(1/2)10−4
=10×9×8×7/4! 1/2^4 1/2^6
=2^44⋅9⋅35/24(2^10)
=105/2^9
