Aptitude - Numbers - Discussion

Discussion Forum : Numbers - General Questions (Q.No. 21)
21.
Which of the following number is divisible by 24 ?
35718
63810
537804
3125736
Answer: Option
Explanation:

24 = 3 x8, where 3 and 8 co-prime.

Clearly, 35718 is not divisible by 8, as 718 is not divisible by 8.

Similarly, 63810 is not divisible by 8 and 537804 is not divisible by 8.

Consider option (D),

Sum of digits = (3 + 1 + 2 + 5 + 7 + 3 + 6) = 27, which is divisible by 3.

Also, 736 is divisible by 8.

3125736 is divisible by (3 x 8), i.e., 24.

Discussion:
56 comments Page 5 of 6.

Dhruv said:   1 decade ago
5+4+7+8+0+4 is not divisible by 3.

Muni said:   1 decade ago
Simply you can do this in this way:

Let factor of 24=4*6.

So just check whether the last two digits are divided by 4 and 6 both then you'll get the answer easily.

Syama said:   1 decade ago
547804 is divisible by 2,3,4 then why its not divisible by 24.. can u explain?

Rafi said:   1 decade ago
3+5+7+1+8 = 24 sum of digit is divisible by 24 then why this not an answer?

Anil said:   1 decade ago
@Rafi ...think dude among four option only one should be divisible by 24.

So 3*8 or 3 into 8..is coprime and then see the divisibility of 3 and 8.

Munir baloch said:   10 years ago
3+5+7+1+8=24 also divisible then why not answer?

Sara said:   10 years ago
I don't understand it please clear my doubt.

Raj said:   10 years ago
Could please any one give clear explanation? Just give me the shortcut method.

Paramjeet said:   9 years ago
As @Malik said.

For example:- If the last digit of any number is 0, 2, 4, 6, 8 then it is fully divided by 2 for example 63470.

That's ok but, what is the last three digit formula for dividing by 8?

Bibek Ranjan Patnaik said:   9 years ago
Both options (c) and (d).

24 = 2 * 3 * 4.
So option (c) 537804 also fulfills all the criteria. It is divisible by 2, 3 and 4. So it also can be the correct answer.

And Please explain why the only (d) option is cited correct?


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