obtaining head in coin

Question

A coin is tossed 10 times Find the probablity of obtaining head at least once

Answer 1

Probability of obtaining head at least once    =  1 - ( Probability of obtaining tail all 10 times)

                                                                       = 1 - (1/2)^10

                                                                       = 1023/1024 

Therefore , probability is 1023/1024

Answer 2

Sample space size $= 1024$
No. of favourable cases $= 1024-1=1023$
Probability $=  \frac{1023}{1024}  =99.90 \%$

Answer 3

1023/1024