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?
A) 0.001
B) 0.002
C) 0.100
D) 0.400
E) 0.600

The answer is D but I can't seem to get the working right.

Question

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? 
A) 0.001 
B) 0.002 
C) 0.100 
D) 0.400 
E) 0.600

The answer is D but I can't seem to get the working right.

dean.shyy · Answer

Maybe you can take a look at this: http://is.gd/48V459