CAT 6 - CR (Inference)

[JbhB682]

A new weight-loss drug causes the loss of body fat in all patients who take the drug. In those same subjects, however, the drug also causes the loss of moderate quantities of lean body mass, where “lean body mass” refers to all body mass other than body fat.

Which of the following statements can be properly inferred from the information in the passage above?

1) Patients taking the new weight-loss drug will not necessarily experience a decrease in their overall percentage of body fat.
2) The body weight of patients taking the new weight-loss drug will not necessarily decrease.
3) The new weight-loss drug contains no chemical that exclusively targets the body’s fat cells.
4) Users of the new weight-loss drug should exercise in order to maintain their current levels of lean body mass.
5) The new drug catalyzes the loss of body fat and the loss of lean body mass via similar mechanisms.

[JbhB682]

Question on the premise specifically

Can one infer the following when reading the word "moderate" quantities

My inference was thinking --- hmmm The person loses more body fat than lean body mass

That was something I understood to be true when i read the word "moderate" quantities.

Is that a wrong assumption to make ?

[Sage Pearce-Higgins]

Yes, that's not a fair assumption to make. In this context 'moderate' doesn't have much meaning, as we don't know what it's being compared with. This is a classic inference problem in that there's a big gap in the phrase "causes the loss of body fat" - but how much?! That's the kind of gap to train yourself to see.

Also, notice how all the wrong answers introduce random extra information, with the exception of B, which is an opposite trap.

[JbhB682]

Thanks Sage .

Just clarifying on another statistic when I read the word "moderate" quantities

I assumed the % change for body fat > % change for lean body mass.

You cannot assume this as well, correct ?

[Sage Pearce-Higgins]

I assumed the % change for body fat > % change for lean body mass

This is exactly the assumption that you cannot make. It seems that you're focusing unduly on the word "moderate". Notice that the passage tells us only that the 'weight-loss drug causes the loss of body fat'. Sure, we need to accept that as true, but it's classic advertising spiel. Think: "but how much?". Perhaps the drug causes a tiny loss of body fat, and a bigger (by %) loss of lean body mass.

[JbhB682]

Thank you Sage.

With regards to C -- is my reasoning to eliminate C accurate in your view ?

This drug reduces BOTH body fat and lean body mass

It's quite possible that this drug has

-- one chemical (lets say chemical A) that targets only body fat
-- another different chemical (lets say chemical B) in the drug targeting only lean body mass

Thus, it's quite possible that you have one chemical (in my example, chemical A) that targets ONLY body fat

What are your thoughts !

Thank you ,

[esledge]

Your reason to eliminate (C) is sound.

In general, the extreme "no chemical" is a reason to doubt (C). The more extreme an answer, the more likely that there are exceptions that make the answer wrong, such as the one you suggest.