multiple substitutions

[nimshad20]

1 particular question, a quantitative comparison question, and a few others i came across, i noticed that sometimes you could only prove D after 3 substitutions. I think once i came across 4. Now because of exam pressure i would stop in 3 trials. maybe even 2.
so what i woud like to know is; are the values im testing wrong or is the question meant to be that way? And if questions are meant to be that way, is there a rule i should follow?

[tommywallach]

Hey Nimshad,

Technically what you're saying doesn't make any sense. You can always prove D with 2 plug-in attempts (don't use the word "substitution," which is a term that relates to algebra; you mean "plugging in"). For example: one attempt makes column A bigger than B, and one attempt makes the two columns equal.

So you can ALWAYS prove D with 2 attempts.

The point you might be making is that sometimes it takes you multiple tries to FIND the 2 numbers that prove D. And yes, it will often take 3, 4, maybe even 5 tries to get there. But you can get better. I like to use the mnemonic device "FONZE:

Fractions
One
Negatives (don't forget negative fractions)
Zero
Extremes

These are number "types" you can try out when plugging in. You want to simply go down the list, but think about which ones might make the difference in helping you get to D.

Hope that helps!

-t

[nimshad20]

thanks for the tip!

[tommywallach]

No problem!

(And by the way, I meant to say you don't want to simply go down the list!).