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 2 of 6.

Madhu said:   1 decade ago
537804 is divisible by 2, 3, 4.

So 537804 is also divisible by 24 na?

If 537804 /24, the remainder will be 0. So the answer will be c and d.

---plz explain why c option cant be the answer

Nikhil said:   5 years ago
The number should be divisible by both 3 and 8.
Here 24 is LCM so among those four options whichever has factors 24 is the answer.
And here only option (D) is satisfying this condition.
(4)

Prakarsh said:   8 years ago
We can not take 2*3*4 because 2&4 are not co primes, hence for 24 only possible co-primes are 8*3.

CO-PRIME: Those prime numbers which have only '1' as a common factor.

THANK YOU

Kartik said:   6 years ago
24= 6 * 4.

The number is divisible by 4 if the last digit of the number is 4 or 6.
The number is divisible by 6 if the last digit of the number is 6.
Therefore option (D).

Nikitha said:   1 decade ago
537804 is divisible by 2, 3, 4.

So 537804 is also divisible by 24 na?

If 537804 /24, the remainder will be 0. So the answer will be c and d.

Can anyone clear my doubt?

ANIL MEGHWAL said:   4 years ago
35718 = 3+5+7+1+8 = 24.
63810 = 6+3+8+1+0 = 18.
537804 = 5+3+7+8+0+4 = 27.
3125736 = 3+1+2+5+7+3+6 = 27.

According to this, concept option 1 should be also correct.
(16)

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.

Swapna said:   5 years ago
Here,
35718=3+5+7+1+8 = 24
63810=6+3+8+1+0 = 18
537804=5+3+7+8+0+4 = 27
3125736 =3+1+2+5+7+3+6 = 27
So, if considering this way then option 1 is correct, right?
(4)

Shubham said:   8 years ago
@Rohit.

May be we need to consider only co-prime numbers to solve the question and we have already tricks to check if the number is divisible by 3 or 8.

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.


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