What is the probability of having red hair and AB negative blood type?

I don't know the odds of having red hair but only about 1 in 20 people are AB (I am also). The solution would be to multiply the two ratios as fractions, IE: if 1 in fifty people are redheads the answer would be 1/20 X 1/50 = 1/1000, or one in 1000.

Approximately 1-2% of people of the human population has naturally red hair. However, about 2-6% of Europeans have red hair, and in Ireland that number is up to 10%. In Asia and Africa, that percentage is down to less than 1%.

The AB negative blood type is the rarest blood type, not including sub groups of each type of blood. (For example A1, A2B, etc.) Only 1 in 167 people have AB-. That means of the human population, there are .7% with blood type AB-. However, very luckily, people with blood type AB negative are still able to have A-, B-, and AB- blood donated, so while it is rare it would still be relatively easy to find a blood donor in the case of an emergency. (Scientists are still trying to determine if O- is acceptable for donation, but they haven't found evidence that would say it is not)

There is an inadequate amount of information to figure how many people have red hair and AB negative blood, but it would be safe to assume it is a very, VERY small amount of people.

Also, to put it in perspective, the human population size is around 6,800,000,000 (6.8 billion) people so 1% would be 68,000,000 (68 million) people.