Aptitude - Numbers - Discussion

Discussion Forum : Numbers - General Questions (Q.No. 81)
81.
The difference of the squares of two consecutive even integers is divisible by which of the following integers ?
3
4
6
7
Answer: Option
Explanation:

Let the two consecutive even integers be 2n and (2n + 2). Then,

(2n + 2)2 = (2n + 2 + 2n)(2n + 2 - 2n)

     = 2(4n + 2)

     = 4(2n + 1), which is divisible by 4.

Discussion:
15 comments Page 1 of 2.

Sreemoy said:   5 years ago
-n +2>0 and 2n >4 the number of integer n satisfying.

Saymon said:   8 years ago
Is it applicable?

x & x+2
so, (x+x+2)^2 =x^2+2.x(x+2)+(x+2)^2 =x^2+2x^2+4x+x^2+2x2+4 = 4x^2+8x+4 = 4(x^2+2x+1).

Kavitha said:   9 years ago
Agree @Prabhu.

a^2 - b^2 = (a + b)(a - b).

Sobhit Kumar Sah said:   9 years ago
@Satyendra.

According to your opinion, there are two answers. Since we take next consecutive even integers 4 & 6.
(1)

Satyendra said:   10 years ago
If we taking two consecutive number as 2 and 4.

Then, we get 12 which is divisible by 3 and 6 also then.

Why we choose 4 only.

16- 4 = 12.

12/3 = 0.

Please clear this doubt.
(1)

Payal said:   10 years ago
But again if we take for odd integers and where x=1 then again the answer is 8 which does not come.

Rumpa said:   1 decade ago
Let two consecutive even integer as x and x+2.

= (x+2)^2-x^2.
= x^2+4x+4-x^2.
= 4x+4.
= 4(x+4).

Divisible by 4.
(4)

Swetha said:   1 decade ago
Why can't we can take consecutive even integers as x, x+2, x+4....where x=2.

Anusha said:   1 decade ago
Eg: Two consecutive even numbers are 6, 8 and 2, 4.

36-64 = 28.
28 is divisible by 4.

4-16 = 12.
12 is divisible by 4.

Shamili said:   1 decade ago
(2n+2)^2!=(2n+2+2n)(2n+2-2n)

It can be write as
(2n+2)^2-(2n)^2=(2n+2+2n)(2n+2-2n)
=(8n+4)
=4(2n+1)

Which is divisible by 4
(1)


Post your comments here:

Your comments will be displayed after verification.