Quote:
A new disease called Probibeleosus has emerged in Oceania. Though non-fatal, Probibeleosus leads to disfigurement, reduced mobility and chronic pain. Medical researchers have thus far discovered two variants of the disease which they have labeled Probibeleosus-A (P-A) and Probibeleosus-B (P-B). Sex partners and siblings of those with P-A are four times as likely as the general population to have P-A. Sex partners of those with P-B are no more likely than the general population to have P-B, but siblings of those with P-B are over eight times more likely to have the disease than the average person.
Which of the following statements is best supported by the above information?
(A) Of those with P.A. their parents would be no more likely than average to have the condition.
(B) Somewhere between one-in-eight and one-in-four people in Oceania have either P-A or P-B.
(C) The sex partners of those who do not have P-A are less likely than average to have P-A.
(D) Those who have never had sex are less likely to have P-B than P-A.
(E) Vulnerability to P-B is more likely hereditary than is vulnerability to P-A.
This is an inference CR question. Hence, we're looking for an answer that MUST be true on the basis of the information given. The info we have is as follows:
P-A seems to be transmitted sexually as well as genetically
P-B is not transmitted sexually, but transmitted more aggressively by genetics
The numbers (1/4, 1/8) are often a red herring on CR questions, trying to get you to balk at the mathematics or furiously dig a hole in trying to get an exact calculation. Remember that the use of logic will far outweigh this, and that all you need is the possibility that an answer is NOT true in order to eliminate it.
A - This is not true. If P-A is influenced by genetics, the parents of someone who has P-A are gonna be more likely to have it. How much more likely? We can't say, but we can say more likely for sure.
OUTB - We don't know this at all. We don't know anything relevant about P-A or P-B and the general population.
OUTC - This could be true, but it could also be false. It's quite possible that a sex partner of someone who does not have P-A could have the disease themselves, or have genetic conditions as well that make them more likely to have it. Remember, we need an answer that MUST be true.
OUTD - This answer as well can be true, but also can be false. We don't know about the overall likelihood rates of P-A or P-B, so either one is more or less possible than the other.
OUTE - Is correct by elimination, but more pertinently, is the direct conclusion of the premises we've been given. P-B has a stronger genetic link. How much stronger? We don't know, but don't need to know, because the claim made in the option isn't that extreme. This answer is therefore
CORRECT - Matoo