Answer:
0.6
Step-by-step explanation:
The ABO system for blood type is determined by a gene with multiple alleles. This means that even though any single individual can have at most two different alleles, in the population there are 3 different alleles in existence: IA, IB and i.
The sum of the frequencies of all the alleles in a population must add up to 1, therefore
freq (IA) + freq (IB) + freq (i)=1
0.3 + 0.1 + freq (i) = 1
freq (i) = 1 - 0.3 - 0.1
freq (i) = 0.6