# DAT Destroyer Question

#### iffyyy

Im working on the DAT destroyer question and circled a few questions to come back to later. In the 2015 version, question number 241 and 242 in the biology section are giving me difficulty. They are very simple questions that ask for the same thing essentially but have different answers. Can someone explain why the variation in the answers?

#### orgoman22

##### DAT DESTROYER
Vendor
10+ Year Member
Im working on the DAT destroyer question and circled a few questions to come back to later. In the 2015 version, question number 241 and 242 in the biology section are giving me difficulty. They are very simple questions that ask for the same thing essentially but have different answers. Can someone explain why the variation in the answers?
241 is actually 2 probabilities,,,,,one is to be a boy...the other is to be normal . You must multiply the two probabilities. 242 is only 1 probability....and that is to have the disease. READ these carefully.....they are merely ' garden variety " Genetics problems.

Hope this helps.

Dr. Romano

alexis2010
OP
I

#### iffyyy

241 is actually 2 probabilities,,,,,one is to be a boy...the other is to be normal . You must multiply the two probabilities. 242 is only 1 probability....and that is to have the disease. READ these carefully.....they are merely ' garden variety " Genetics problems.

Hope this helps.

Dr. Romano
Thanks for the quick reply! I am still sort of confused as question 242 also states 'couple's son + hemophilia' unless you are supposed to negate the probability of them having a son?

#### Graffix

2+ Year Member
Thanks for the quick reply! I am still sort of confused as question 242 also states 'couple's son + hemophilia' unless you are supposed to negate the probability of them having a son?
For 241 I see it like this: what is the probability that their (Bill and Ann) first child (so 100 percent they're having a kid, we don't know gender yet) will be a normal (probability 1, he could be color blind or not) and a boy (probability 2, the child could be a boy or girl). So we have to multiply 2 probabilities.

For 242: I woman marries a man. What is the probability that the couple's son (they had a baby boy, 100 percent. they "already have the son" so it definitely cant be a girl) will have hemophilia (Only probability of the question)? IF the question was rewritten as "What is the probability that the couple will have a son that will have hemophilia?" then we would also consider the gender probability.

Hope this helps!

OP
I

#### iffyyy

For 241 I see it like this: what is the probability that their (Bill and Ann) first child (so 100 percent they're having a kid, we don't know gender yet) will be a normal (probability 1, he could be color blind or not) and a boy (probability 2, the child could be a boy or girl). So we have to multiply 2 probabilities.

For 242: I woman marries a man. What is the probability that the couple's son (they had a baby boy, 100 percent. they "already have the son" so it definitely cant be a girl) will have hemophilia (Only probability of the question)? IF the question was rewritten as "What is the probability that the couple will have a son that will have hemophilia?" then we would also consider the gender probability.

Hope this helps!
OK that clarifies it! For the question you assume that they already had a boy meaning theres only one probability to calculate. Thanks alot!

Graffix