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number system

by vipulgoyal » Thu Sep 12, 2013 12:17 am
what is the sum of the digits of the positive integer n where n<99 ??
1. n is divisible by the squre of Y
2. y^4 is a two digit positive odd integer
later
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by ganeshrkamath » Thu Sep 12, 2013 12:37 am
vipulgoyal wrote:what is the sum of the digits of the positive integer n where n<99 ??
1. n is divisible by the square of Y
2. y^4 is a two digit positive odd integer
later
1. Not sufficient.

2. y^4 is a 2 digit odd number
Since nothing is mentioned about n, this is not sufficient.

Both:
n = y^2 * Q (Q is a positive integer)
y^4 is a positive odd 2-digit integer.
Case 1: y^2 = 7 => y^4 = 49 and n = multiple of 7
Case 2: y^2 = 9 => y^4 = 81 and n = multiple of 9
We cannot find the sum of the digits of n.
Not sufficient.

Choose E

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by vipulgoyal » Thu Sep 12, 2013 12:57 am
If y would have been int then the ans is C and the sum of digits is 9
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by vinay1983 » Thu Sep 12, 2013 1:40 am
Statement 1

Some number less than 99 that is a square of some othet number....Insuf

Statement 2

I could think of 16 and 81. 2 answers so Insuff

Combining

16 is divisible by 2^2 and 81 is divisible by 3^2. 2 answers In sufficient

Should be E
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by vipulgoyal » Thu Sep 12, 2013 2:04 am
Vinay, reconsider you ans, statement 2 says "y^4 is a two digit positive odd integer"

y could be root5 or root 7 or 3 but not 2
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by vinay1983 » Thu Sep 12, 2013 2:26 am
vipulgoyal wrote:Vinay, reconsider you ans, statement 2 says "y^4 is a two digit positive odd integer"

y could be root5 or root 7 or 3 but not 2
Yep sorry for that.My bad.So 2 can be rreplaced by √5 or √7 as you said. Thanks man.

For "√" hold Alt tab and then type "251" on number pad simultaeonously
You can, for example never foretell what any one man will do, but you can say with precision what an average number will be up to!
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