Math Is Fun Forum / Play with numbers

smiyc86 · 2009-03-27 22:06:45

A= 1999^1999
B = sum of digits of A
C = sum of digits of B
D = sum of digits of C

find the sum of digits of D

smiyc86 · 2009-03-27 22:15:37

et N = 1111...(upto 3^x digits) ... where x ∈ N

prove that N is divisible by 3^x

smiyc86 · 2009-03-27 22:17:07

A number of 9 digits has the following properties:
The number comprising the leftmost two digits is divisible by 2, that comprising the leftmost three digits is divisible by 3, the leftmost four by 4, the leftmost five by 5, and so on for the nine digits of the number i.e. the number formed from the first n digits is divisible by n, 2<=n<=9.

Each digit in the number is different i.e. no digits are repeated.

The digit 0 does not occur in the number i.e. it is comprised only of the digits 1-9 in some order.
Find the number.

smiyc86 · 2009-03-27 22:32:40

A * B * C = B * G * E = D * E * F

all the letters have 1-to-1 mapping with single digit numbers.

find the value of G

JaneFairfax · 2009-03-28 07:48:18

smiyc86 · 2009-03-30 17:27:43

#5

now dis is a good one ...

A sequence of positive real numbers is defined as:

Y(0) = 1
Y(n+2) = 2*Y(n) - Y(n+1), for n = 0, 1, 2, ...

What is the value of Y(2007)?

smiyc86 · 2009-03-30 17:50:03

i forgot giving a hint for #4 .... here it goes

try this figure.

A D

B G E

C F

smiyc86 · 2009-03-31 18:14:34

@jane ...

smiyc86 · 2009-03-31 18:50:43

#6

I am a three digit number.

I am divisible by 3 or by 5.
I am divisible by 4 or by 6.
I am divisible by 5 or by 7.
I am divisible by 6 or by 8.
I am divisible by 7 or by 9.
I am divisible by 9 or by 11.

What am I?

Last edited by smiyc86 (2009-03-31 20:56:33)

ganesh · 2009-04-01 00:24:43

smiyc86 · 2009-04-01 17:36:27

@ganesh ... answer is incorrect .... further post ur approach ... no need to post the solution just the approach .... look for the hint dude ...

ganesh · 2009-04-01 18:42:37

smiyc86,

smiyc86 · 2009-04-01 19:18:52

ganesh,

ganesh · 2009-04-01 22:50:48

smiyc86 · 2009-04-03 20:23:01

yepp now u r rite ...

JaneFairfax · 2009-04-04 09:24:58

smiyc86 wrote:

By convention, “or” in mathematics is taken to mean the inclusive “or”, unless otherwise specified. Since you are not using it in the inclusive sense in your problem, you should have explicitly stated it in the first place.

smiyc86 · 2009-04-04 17:00:16

@jane ... sometymes u need to be good in english to solve math problems ....

u shud interpret the prob properly by understanding what is written ..... use ur brains .... not ur math laws ..... btw math states only one law "logic" .... if u aren't good in that ... u lll remain as stucck to formula etc. as u currently are .....

ganesh · 2009-04-04 17:29:07

smiyc86,
Its funny you are taking about being good in English to JaneFairfax!
The words you used are not the kind you use when addressing a person of the caliber of Jane.
I am not being criticial, please treat this as a friendly advice.

smiyc86 · 2009-04-04 17:35:10

ohh dun worry brother ... if i have ne prob i say directly ... and if i feel someone stupid i say it to his/her face ... i dun care who he/she is ... few exceptions are people i respect ... and by no way i feel this girl falling in the "exception" category ... u r talking as if she is the math teacher out here ... let me tell u one thing dude .... her ways are very formula oriented and generally comes from people who are bookish in nature ... i dun care who u ppl are in this forum ... and i dun give a $bit$ to what u ppl care ... to me "what is right will remain so and what is wrong i ll try to correct it or despise it "

ganesh · 2009-04-04 17:42:06

smiyc86 wrote:
... few exceptions are people i respect ... and by no way i feel this girl falling in the "exception" category ... u r talking as if she is the math teacher out here ...

Okay, you are entitled to your views. For your information, everyone's on par here. But you got to respect a person who has contributed a lot to the forum. I have nothing more to say.

smiyc86 · 2009-04-04 17:51:18

i never disrespect anyone ... i can understand how u feel ..... u know her for long .... but she took against me for a long tym ... and i respect those ppl who returns the same to me ... as long as i am here in this forum ... she in no way will earn respect back from me .. for example here u were solving the problem ... u didn't have ne issues ... once i told u to read the statements properly ... nd btw ... OR here in no way meant that it can be div by both ... u cannot implicitly arrive to a conclusion of ur own .... she can teach me math ... but can't teach me logic and interpretations ....

and even if i am wrong .... she shud have the MANNERS to tell me .... if she doesn't have ... she better learn it from somewhere

Identity · 2009-04-04 18:22:07

smiyc86 wrote:
OR here in no way meant that it can be div by both ... u cannot implicitly arrive to a conclusion of ur own ....

The standard definition of 'OR' is inclusive. Standards are created so misunderstanding cannot occur, so if you don't agree with a standard then it is your responsibility to explain your own definition in the problem statement, otherwise everybody will assume the standard definition.

But anyway, this is a trivial matter, nothing to get too fussed or upset about, I thought Jane was quite mannered in her post.

Last edited by Identity (2009-04-04 18:26:56)

smiyc86 · 2009-04-04 19:07:24

let us stop this nonsense discussion .... ok mayb i did a mistake ... i dun wanna spoil everybody's mood ... it's just that girl argued without any sense in the another thread that i was really pi$$d off with her ....

JaneFairfax · 2009-04-04 20:15:01

smiyc86, please don’t get me wrong. I wasn’t criticizing you.

I was just pointing out that your style is different from the conventional one, so it’s your own responsibility to make clear at the start what your style is. Now, you choose to treat “or” as exclusive (unless otherwise specified). Conventional mathematics, however, treats “or” as inclusive (unless otherwise specified). You are not wrong, only different. You should therefore state your “difference” at the beginning. Once we know what your style is, we can all adapt to it with no difficulty.

I have my own idiosyncratic ways of doing maths too. When I feel that what I am doing may cause confusion with the mainstream, I always go out of my way to explain myself so I’m not misunderstood.

Last edited by JaneFairfax (2009-04-04 22:13:20)

smiyc86 · 2009-04-15 21:21:43

there's another way of solving #2

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#1 2009-03-27 22:06:45

Play with numbers

#2 2009-03-27 22:15:37

Re: Play with numbers

#3 2009-03-27 22:17:07

Re: Play with numbers

#4 2009-03-27 22:32:40

Re: Play with numbers

#5 2009-03-28 07:48:18

Re: Play with numbers

#6 2009-03-30 17:27:43

Re: Play with numbers

#7 2009-03-30 17:50:03

Re: Play with numbers

#8 2009-03-31 18:14:34

Re: Play with numbers

#9 2009-03-31 18:50:43

Re: Play with numbers

#10 2009-04-01 00:24:43

Re: Play with numbers

#11 2009-04-01 17:36:27

Re: Play with numbers

#12 2009-04-01 18:42:37

Re: Play with numbers

#13 2009-04-01 19:18:52

Re: Play with numbers

#14 2009-04-01 22:50:48

Re: Play with numbers

#15 2009-04-03 20:23:01

Re: Play with numbers

#16 2009-04-04 09:24:58

Re: Play with numbers

smiyc86 wrote:

#17 2009-04-04 17:00:16

Re: Play with numbers

#18 2009-04-04 17:29:07

Re: Play with numbers

#19 2009-04-04 17:35:10

Re: Play with numbers

#20 2009-04-04 17:42:06

Re: Play with numbers

smiyc86 wrote:

#21 2009-04-04 17:51:18

Re: Play with numbers

#22 2009-04-04 18:22:07

Re: Play with numbers

smiyc86 wrote:

#23 2009-04-04 19:07:24

Re: Play with numbers

#24 2009-04-04 20:15:01

Re: Play with numbers

#25 2009-04-15 21:21:43

Re: Play with numbers

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