questionr
Early access
Exams
Joint Entrance Examination
Mathematics
Probability
Question 225
Question 225 of 417
Easy
MCQ
Find the minimum number of coin tosses so
P
(
at least one head
)
>
99
%
P(\text{at least one head})>99\%
P
(
at least one head
)
>
99%
.
A
5
B
6
C
8
D
7
Check answer
Press A-D to select · Enter to check
Solutions · 1
Post your solution
Official solution
\[1-\left(\frac12\right)^n>0.99 \implies \left(\frac12\right)^n<0.01 \implies n\ge7\]
Answer the question to unlock
Previous
Next