Aptitude - Numbers - Discussion

In place of * keep x for better understanding.
5 + x + 2 = 7 + x.

The lcm of(9) is 3*3 so 3 should be also divisible by 7+x,
if x=2 7+2 =9 which is divisible by 3.

(5 + 2) = 7,
7 + 4 = 12,
12/2 = 2,
Ans = 2.

Thank you @Pooja.

From divisibility test method,

->A number is divisible byv'6' if the number is even and the sum of the digits is divisible by '3'.

Lets the number be 5x2.

Here the given number 5x2 have already an even number at its unit digit,so 5x2 is an even number,

Now by using all the given options we have to check the sum of the digits may or may not divisible by '3'.

From opt.(A) x=2, 5+2+2=9,i.e divisible by '3' .
From opt.(B) x=3, 5+3+2=8,i.e, not divisible by'3'.
From opt.(C) x=6, 5+6+2=13,i.e, not divisible by '3'.
From opt.(D) x=7, 5+7+2=14,i.e, not divisible by '3'.
Hence opt.(A) i.e, '2' is the answer.

Hi. It is very simple.

5*2 is divisible by 6(by the hypothesis).
So 6=3X2.so 5*2 is divisible by 2 and 3.
5*2 is perfectly divisible by 2.Because in that one's place can have 2.
5+x+2is divisible by 3.

So 5+2+2=9 is can divisible by 3.

So that the answer 2 is correct. I mean that the option "A" is correct.

It is not understand. Please explain it.

Put option A in place of *, it is perfectly divisible by 6.

Put option B in place of *, it is not perfectly divisible 6.

Put option C in place of *, it is not perfectly divisible 6.

Put option D in place of *, it is not perfectly divisible 6.

Therefore option A is the answer.

(We know:
(i) If the one's place of number is 2, then the given whole no. will be divisible by 2.
(ii) If the total of given number is divisible by 3, then the
whole no. will be divisible by 3.
(iii) If the given no. is divisible by 2 & 3, then the given no. will be divisible by 6.)

So, in the solution the given number is " 5*2 ".
Now we substitute the first option [A] 2, in " * " place.
The one's place is "2" so that no. was divisible by 2.
Next (5+2+2) = 9. so the given no. was divisible by 3.
Therefore, the number was divisible by 6.

I don't understand can you explain me the method in brief.