[Guest]

I recently added the Puzzles and Riddles gadget on iGoogle and found this:

3

What is the nearest percentage of all numbers containing at least a single '3':

[1] 10%

[2] 13%

[3] 33%

[4] 67%

[5] 100%

For example, 13, 31, 33 and 103 all contain the digit 3 at least once. But 1, 2, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, ... well you get the idea ... don't contain the digit 3 even once.

The link to the solution was broken and a few searches proved futile. I've got a guess at the answer after a napkin calculation, but I'd like to see what people have to say.

My apologies if this is old (I presume it is).

Cheers,

Adam

[Guest]

The nearest is 3(three) percent

[Guest]

I recently added the Puzzles and Riddles gadget on iGoogle and found this:

3

What is the nearest percentage of all numbers containing at least a single '3':

[1] 10%

[2] 13%

[3] 33%

[4] 67%

[5] 100%

For example, 13, 31, 33 and 103 all contain the digit 3 at least once. But 1, 2, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, ... well you get the idea ... don't contain the digit 3 even once.

The link to the solution was broken and a few searches proved futile. I've got a guess at the answer after a napkin calculation, but I'd like to see what people have to say.

My apologies if this is old (I presume it is).

Cheers,

Adam

The answer is approaching very close to 100% i.e., 99.9999... %

[Guest]

I have never heard this "Percentage of 3s" before so I am not sure if my answer is correct.

Since the numbers go on infinitely I would only look at the first 100. My reasoning would be that all numbers after 100 are really repetitive, 300's, 3000's, they all are counted within their respective sets, 300's would be assumed that you only count to 1000, 3000's would be 10000, so on and so forth. I am guessing that the riddle is also meant to throw people off due to the numbers that have more then one 3 in it, in other words, you would accidentally count 33 twice.

So, now we look at the first 100. 3, 13, 23, 43, 53, 63, 73, 83, and 93, so 9 numbers so far. Then we add the 30-39 and we come up with 10 more. My calculations show that the correct percentage is 19%, which is not one of the choices, so the closest would have to be answer is number 2, 13%. I also believe that the 33% answer is also meant to throw one off...

[Guest]

my estimatation comes close to 19% or ~20%, i can explain, if someone thinks the need for it

Edited March 19, 2009 by tarunark

[rookie1ja]

Welcome to the Den, Sycobob. I did a quick search for "What is the nearest percentage of all numbers containing" from the home page and found the following topic.

You are absolutely right about the missing link to solution in the Google gadget. Thanks for pointing that out. I have added the link in the gadget.

Enjoy the Den

Thread locked.