Hardy Wein Berg Equilibrium problem

[jackieabbott]

Hello,
Can anybody help me with this?
I'm completely stumped and have an exam tomorrow.

8. A population of white-clover plants on the coast of Wales includes individuals that release
cyanide when their leaves are damaged (cyanogenic plants) and those that do not (acyanogenic
plants). These differences in cyanide production are controlled by two alleles at a single locus,
with the "cyanogenic" allele being completely dominant to the "acyanogenic" allele. Because
cyanide production discourages feeding by land snails, acyanogenic plants have 20% lower
survival than cyanogenic plants. Suppose that clover plants that survive to reproduce produce
equal numbers of seeds, regardless of their cyanogenesis phenotype. If the acyanogenic allele
represents 30% of the gene pool of one generation, what proportion of clover plants zygotes
would be cyanogenic in the next generation?
A. 0.981
B. 0.918
C. 0.566
D. 0.073
E. 0.019


THANK YOU!

[JackBean]

I'll use c and a instead of standard p and q)

a = 0.3 -> c = 1 - a = 0.7
aa = 0.3^2 = 0.09
20% of 0.09 = 0.018, i.e. there will be next year 0.09 - 0.018 = 0.072
Thus there will be of cyanogenic plants: 1 - 0.072 = 0.928
which does not fit to any option There is probably typo in the answers.