The problem of 2 children

[boolean]

my dear friend La La asked me to post some new riddle to this board and I am ready for that -


Some one says to you that " I have two children . This is the elder one, his name is Peter" . Now , as you dont know about the second child, what is probability of the second child being male... (( also tell the probability of his/her being female ))


Seems straight , but it is not !!!

[Kelsey]

There is a 50% chance it being male and a 50% chance that it's female.