CR ques

[AnuragRatna]

Many banks have a drive-through automated teller machine, built into the wall flanking the driver's side of a narrow aisle. Even though blind people obviously do not drive, these machines nonetheless invariably feature Braille - the system of raised dots used by the blind for reading and writing - in addition to the standard letters and numerals on their control panels.

Which of the following, if true, does the most to explain the situation described?


In most automobiles, the rear windows on the driver's side only roll down about halfway.

Moderately visually impaired people who are still allowed to drive typically do not use Braille to read or write.

Blind people can often read Braille just as quickly and accurately as sighted people can read regular writing.

The embossing technique used to form the raised dots does not typically add much to the overall cost of the automated teller machine.

In order to maximize profits per unit, manufacturers produce only a single model of automated teller machine.

[Jim@StratusPrep]

1) Not important
2) This is a reason to not have Braille
3) Not relevant
4) Okay, but doesn't explain why these tellers would have Braille
5) The company makes more money by producing just one model - therefore even locations that don't need Braille will have it.

[ceilidh.erickson]

Whenever we're asked to explain a surprising situation, we need to close the gap between our expectations and reality.

Given: blind people don't drive, and ATMs on are the driver's side
Expect: no Braille, since only blind people use it
Actual: there is Braille on the ATMs

In order to explain this, we need to add a piece of information that does one of the following:
1) explain why blind people who are not driving might use a drive-up machine
2) explain why this machine might have some other reason to have Braille on it (legal reasons, monetary reasons, etc).

A. In most automobiles, the rear windows on the driver's side only roll down about halfway.

This would suggest that blind people cannot use the ATM from the rear of the vehicle, so this doesn't explain it.

B. Moderately visually impaired people who are still allowed to drive typically do not use Braille to read or write.

If they don't use it, there's no reason for it to be there.

C. Blind people can often read Braille just as quickly and accurately as sighted people can read regular writing.

This does nothing to explain why it's at a drive-up ATM.

D. The embossing technique used to form the raised dots does not typically add much to the overall cost of the automated teller machine.

Just because it doesn't add to the cost, that doesn't explain why it's there for no reason.

E. In order to maximize profits per unit, manufacturers produce only a single model of automated teller machine.

If there's only one model, we can infer that it's also in non-drive-up locations, where blind people actually would use it. Correct.

[David@VeritasPrep]

I really like this paradox question!

Thanks for posting this one. It is a fun question and the answer is certainly beyond dispute.