Aptitude - Numbers - Discussion

Discussion Forum : Numbers - General Questions (Q.No. 102)
102.
If the number 91876 * 2 is completely divisible by 8, then the smallest whole number in place of * will be:
1
2
3
4
None of these
Answer: Option
Explanation:

Then number 6x2 must be divisible by 8.

   x = 3, as 632 is divisible 8.

Discussion:
17 comments Page 1 of 2.

Alfraz said:   4 years ago
Divisibility rule for 8:

Check the last 3 digits;

If the 3rd last digit is even then check if the number formed by the last 2 digits is divisible by 8. If yes then it is divisible.

If the 3rd last digit is odd then check if the number formed by the last 2 digits + 4 is divisible by 8. If yes then the number is divisible.

In this example:

The 3rd last digit is 6 which is even and the number formed by the last two digits must divisible by 8. Hence the 2nd last digit should be 3 as 32 is divisible by 8.

Hope it helps.
(1)

Alfraz said:   4 years ago
Divisibility rule for 8:

Check the last 3 digits;

If the 3rd last digit is even then check if the number formed by the last 2 digits is divisible by 8. If yes then it is divisible.

If the 3rd last digit is odd then check if the number formed by the last 2 digits + 4 is divisible by 8. If yes then the number is divisible.

In this example:

The 3rd last digit is 6 which is even and the number formed by the last two digits must divisible by 8. Hence the 2nd last digit should be 3 as 32 is divisible by 8.

Hope it helps.
(2)

Vinod said:   7 years ago
The given no is completely divided by 8 only when last three digits are completely divided by 8.
here last three digits are 6*2.

If we put 3 in place of * then it will completely be divided by 8. Hence 3 is the answer.
Hope all got it now.

Sivakumar.K said:   1 decade ago
To substitute x=0, x=1, x=2, x=3....x=9.

When x=3 to substitute in between "6x2" is completely divisible by 8 and it's not given remaining value, if you have any doubt to substitute x=0 up-to 9 in between "6x2".

Ramesh said:   9 years ago
91876 x 2 is divisible by 8.
9 + 1 + 8 + 7 + 6 + x + 2 is divisible by 8.
33 + x is divisible by 8.
So smallest value of x = 7 is divisible by 8.
So the answer is none of above.

Pankil said:   8 years ago
6 x 2 (where x=7 also divisible by 8) and 9187672 also divisible by 8.

So that, we can get an answer with a Two-way number.

Chan said:   9 years ago
Hi @Sasi.

9187632 is completely divisible by 8.

Once again check it.

Sasi said:   1 decade ago
Last 3 digits are divisible by 8. When put x=3. Other can't exist.

Shalima shalaka said:   1 decade ago
How can we know that the answer is 3 please explain?

Aparna said:   1 decade ago
Is it last 3 digits or 2 digits please tell me?


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