You never have an around 100% chance. You always have less. The chance of at least one out of ten making it if they have 10% chance each is: 1-0.9^10, that's tw

You never have an around 100% chance. You always have less. The chance of at least one out of ten making it if they have 10% chance each is: 1-0.9^10, that's two thirds. In other words: In a society where 90% of children die and women have 10 births, one third of the mothers will lose all. All assuming the deaths are independent of course.