As often ... I came up with the right solution but wonder myself if I've done it properly or just arrived at it by accident.
Isn't the solution pretty obvious? I dared to press the button because I thought there has to be a trap!
But basically if you assume 100 voters -> 15 voters were female and below the age of 30
Now we know that 50% of the voters below the age of 30 were not females
That means they split each other in a 15 / 15 group to get this ratio of 50% not females
therefore 30/100
...
Isn't the solution pretty obvious? I dared to press the button because I thought there has to be a trap!
But basically if you assume 100 voters -> 15 voters were female and below the age of 30
Now we know that 50% of the voters below the age of 30 were not females
That means they split each other in a 15 / 15 group to get this ratio of 50% not females
therefore 30/100
...