In a hypothetical population of 1,000 people, tests of blood-type genes show that 160 have the genotype aa, 480 have the genotype ab, and 360 have the genotype bb. what is the frequency of the b allele?

This question can be solved using Hardy-Weinberg equation. The equation would be:

a+b=1

a^2+2ab+b^2=1

There are 360 individual with genotype bb which means

b^2=360/1000

b = √0.36 = 0.6

The frequency of b allele would be: 0.6