Aptitude - Numbers - Discussion
Discussion Forum : Numbers - General Questions (Q.No. 3)
3.
It is being given that (232 + 1) is completely divisible by a whole number. Which of the following numbers is completely divisible by this number?
Answer: Option
Explanation:
Let 232 = x. Then, (232 + 1) = (x + 1).
Let (x + 1) be completely divisible by the natural number N. Then,
(296 + 1) = [(232)3 + 1] = (x3 + 1) = (x + 1)(x2 - x + 1), which is completely divisible by N, since (x + 1) is divisible by N.
Discussion:
137 comments Page 4 of 14.
Madhu said:
1 decade ago
I have one solution.
Let 232 = x. Then, (232 + 1) = (x + 1).
Let (x + 1) be completely divisible by the natural number N. Then
[(232)3 + 1] = (296 + 1) =(x3 + 1) = (x + 1)(x2 - x + 1), which is completely divisible by N, since (x + 1) is divisible by N.
Let 232 = x. Then, (232 + 1) = (x + 1).
Let (x + 1) be completely divisible by the natural number N. Then
[(232)3 + 1] = (296 + 1) =(x3 + 1) = (x + 1)(x2 - x + 1), which is completely divisible by N, since (x + 1) is divisible by N.
S.kishore sulthana said:
1 decade ago
Given :(2)^32+1 is a whole number
we find that: which number from the following option is divisible by this whole number.
I have one best solution
let 2^32=X, now,given: (2^32)+1=X+1,
THEN CHECK any option,
first OPTION A, (2^16)+1,
IT IS TOO small number than given number,so it is not divisible by the given number.
therefore,it is wrong.
SECOND OPTION B, (2^16)-1,
IT IS also a TOO small number than given number,so it is not divisible by the given number.
therefore,it is wrong.
THIRD OPTION C,7*(2^23)
Here (2^23) is too small number than the given number.
so it is not divisible by given number
then Final FOURTH OPTION D, (2^96)+1,
here 2^96 is biggest number than (2^32)
so (2^96)+1 is divisible by (2^32)+1,
EXPLANATION: let (2^32)=X,
here let write(2^32)^3=2^96(for our convenience)
option4:(2^96)+1, therefore, [(X)^3]+1
we know the formula:(a^3+b^3)=(a+b)(a^2-ab+b^2)
from the above :write [(x^3)+(1)^3)=(x+1)(x^2-x+1)
here (x+1)(x^2-x+1)is divisible by (X+1) that is given number..
we know that (X+1)=(2^32)+1=given number..
Therefore the option4 is divisible by given number.
so,it is a correct answer friends...
we find that: which number from the following option is divisible by this whole number.
I have one best solution
let 2^32=X, now,given: (2^32)+1=X+1,
THEN CHECK any option,
first OPTION A, (2^16)+1,
IT IS TOO small number than given number,so it is not divisible by the given number.
therefore,it is wrong.
SECOND OPTION B, (2^16)-1,
IT IS also a TOO small number than given number,so it is not divisible by the given number.
therefore,it is wrong.
THIRD OPTION C,7*(2^23)
Here (2^23) is too small number than the given number.
so it is not divisible by given number
then Final FOURTH OPTION D, (2^96)+1,
here 2^96 is biggest number than (2^32)
so (2^96)+1 is divisible by (2^32)+1,
EXPLANATION: let (2^32)=X,
here let write(2^32)^3=2^96(for our convenience)
option4:(2^96)+1, therefore, [(X)^3]+1
we know the formula:(a^3+b^3)=(a+b)(a^2-ab+b^2)
from the above :write [(x^3)+(1)^3)=(x+1)(x^2-x+1)
here (x+1)(x^2-x+1)is divisible by (X+1) that is given number..
we know that (X+1)=(2^32)+1=given number..
Therefore the option4 is divisible by given number.
so,it is a correct answer friends...
Bappa said:
1 decade ago
I am confusing. (2^32 + 1) is completely divisible by (2^96 + 1) OR (2^96 + 1) is completely divisible by (2^32 + 1). Sorry, perhaps I can't understood the question.
Hasan said:
1 decade ago
Suppose X = 2^32 then 2^32+1 = X+1.
2^96 + 1
= (2^32)^3 + 1
= X^3 + 1. .'. (2^32 = X)
Let X^3+1/X+1
(X+1)(X^2 - X + 1) / (X+1)
=(X^2 - X + 1).
Which is completely divisible by N, since (x + 1) is divisible by N.
2^96 + 1
= (2^32)^3 + 1
= X^3 + 1. .'. (2^32 = X)
Let X^3+1/X+1
(X+1)(X^2 - X + 1) / (X+1)
=(X^2 - X + 1).
Which is completely divisible by N, since (x + 1) is divisible by N.
Mandar said:
1 decade ago
In simple words.
Guy's just look at the power of each no. It is lesser than the (2^32+1) they ask us to completely divisible by (2^32+1).
So Only (2^96+1) Has The Greater power Than the other given No. So Answer is (2^96+1).
Because to divide NR. completely power of the NR. Or no in NR. it has to be greater than Dr.
Guy's just look at the power of each no. It is lesser than the (2^32+1) they ask us to completely divisible by (2^32+1).
So Only (2^96+1) Has The Greater power Than the other given No. So Answer is (2^96+1).
Because to divide NR. completely power of the NR. Or no in NR. it has to be greater than Dr.
Anshul said:
1 decade ago
Put X =3 in place of X in Expression (X+1)(X^2-x-1),
Then 4 * (9-3-1).
= 4 * 5.
= 20.
Which is divided by (x+1) means 4.
Hence BY if "a" is divided by "b"
b is divided by C.
Then a is divided by C.
Hence x^3+1 is divided by X+1 , & X^3+1 is 2^96+1.
Then 4 * (9-3-1).
= 4 * 5.
= 20.
Which is divided by (x+1) means 4.
Hence BY if "a" is divided by "b"
b is divided by C.
Then a is divided by C.
Hence x^3+1 is divided by X+1 , & X^3+1 is 2^96+1.
Srujana said:
1 decade ago
I can't understand how to replace (2^96+1) please explain?
D.raja said:
1 decade ago
I don't understand this answer please explain briefly. How to replace this answer (2^96+1)?
Navin kumar kamti said:
1 decade ago
Its very simple try to understand friend.
Here,
Let suppose x+1 divisible by n where n is natural number as like 0. 1.2.3....
If put x=1 then,
x+1=1+1=2.
Which is divisible by n.
As like,
2/2=0.
Thus,
2^32=x suppose.
Then we can write,
x+1= 2^23+1.
Now (2^23)^3+1) = 2^96+1.
Now we can write,
Formula of (x^3+1) = (x+1)(x^2-x+1) which is divisible by n nis natural no As like 0.1.2.....n
since x+1 divisible by n.
Here,
Let suppose x+1 divisible by n where n is natural number as like 0. 1.2.3....
If put x=1 then,
x+1=1+1=2.
Which is divisible by n.
As like,
2/2=0.
Thus,
2^32=x suppose.
Then we can write,
x+1= 2^23+1.
Now (2^23)^3+1) = 2^96+1.
Now we can write,
Formula of (x^3+1) = (x+1)(x^2-x+1) which is divisible by n nis natural no As like 0.1.2.....n
since x+1 divisible by n.
Senthil kumar said:
1 decade ago
I cannot understand how this (2^23)^3+1 is created.
Please explain sir.
Please explain sir.
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers