How many 9 exists between 0 and 100?

Question

This question was asked in a TV program in Brazil in other times.

It generates many discursion because has double interpretation!

The person that participated of program doesn't answered because this question was valid 500.000 US$!

Do you know?

I have three answers to this question!

It depends only of our interpretation!

Answer 1

if we think of nine as a digit its Infinate-dont forget about decimals-0.9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999 9999999999
Already has 500 and i havent even gotten to 1 yet

but if I limit myself to just 5 decimal places and only go up to 3.24599 there are 24,753,658,145,789,456 thats right 24.75 quadrillion, I dont think i need to go any further. I think everybody get the idea that the correct answer is infinate.

however, one could also think of nine as the number and say that there is only one true nine (the one that comes after 8 and before 10.

there is also the answer 20...which is thoroughly incorrect because if you are referring to nine the digit and not nine the number you must also include deciamls...but clearly the question asker is taking it easy on the not so bright people who answered 20, because he is accepting it as a correct answer aswell

Answer 2

Three possible answers:

1. 20 -- the "9" digits in 9, 19, 29, 39, 49, 59, 69, 79, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, and 99.
2. Only one -- *if* the question was asked as "how many times does the number 9 exist between 0 and 100," because there's a difference between a number and a digit.
3. An infinite number of times. For instance, the number 71.3059999999999999999... is between 0 and 100 and contributes an infinite number of 9's to the count. This is an issue of the unstated assumption that only natural numbers were to be used -- but even if you explicitly ask for natural numbers only, you can still write the number 1 as 0.999999999... so the "infinite number" answer can still be considered correct.

Hope that's what you were looking for. :)

Answer 3

there are 11 9's between 0 and 100....
9 19 29 39 49 59 69 79 89 99

Answer 4

There are 20

9, 19, 29, 39, 49, 59, 69, 79, 89. 90, 91, 92, 93, 94, 95, 96, 97, 98, 99

Remember ther are two 9s in 99.

And the same is true of all numbers 1-9


Of course you can interpret the question more literally and say there is only one, just the number 9 itself. (ie. 19 is not the same as 9)

Answer 5

20
9 19 29 39 49 59 69 79 89 =9
90 91 92 93 94 95 96 97 98 =9
99 =2

Add em up and what have you got??
(Rainman again)
20 definitely 20

Chris

Answer 6

INterpretation one: There is only one nine. The number 9

Interpretation two: count the number of times you see 9 in the numbers from 1 through 1000: 9,19....90,91,92,93...99: Answer 20.

Interpretation 3: HOw many nines go into 100. eg 9, 9+9 (18), 27, 36, Answer: 11

Interpretation 4: ALL (since all nines anyway exist between 0 and 100) in fact all of them exist between 7 and ten.

Answer 7

Nineteen, if you include the two "9"'s in 99 (9, 19, 29, 39, 49, 59, 69, 79, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99).

Answer 8

11

Answer 9

11

Answer 10

20

Answer 11

20