<p>can somebody look at this question and tell me whats the answer, i think barrons book is kinda messed up (PG 297 Number 15 , Practice Test 2)
15. A Color-blind man married a normal woman who is heterozygous for color vision. what is the probablilty that their TWO daughters will be color blind?
(A) 0
(B) 1/8
(C) 1/4
(D) 1/2
(E) 3/4
Should it be 1/4, Cause it says TWO daugthers? or am i missing something..
And for anybody who has the barrons book, goto page 302 and uhh...why is the answer NOT e??</p>
<p>Man: XcY
woman: XcX</p>
<p>A daughter always receives Xc from this father. She will be colorblind if she recieves Xc from the mother as well, so there is a 1/2 chance.</p>
<p>Since it is asking for the probability that both will be colorblind, the answer should be (1/2)*(1/2)=1/4.</p>
<p>YES SOMEBODY AGRESS WITH ME....The barrons Book says 1/2 i dunno why......o and can u plz look at da other question if u have the barrons book?</p>
<p>sorry, i don't have barron's</p>
<p>this is really easy man:</p>
<pre><code>XC Xc
</code></pre>
<p>Xc XXCc XXcc The probability of one daughter getting color blind is 1/2. It dosen't matter how many daughters he has, the probability of one half will be there for every child.</p>
<p>thats what confused me , shouldnt u multiply 1/2 * 1/2 cause it said TWO daughters not one??</p>
<p>No..that's what I thought at first...just assume that when they ask it, they mean what is the probability of EACH of the two getting it...and its 1/2 for both, so it's 1/2.</p>
<p>hopefully the real test will be clearer</p>