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 1 of 6.

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.
(14)

Srikanth said:   4 years ago
Thanks @Naresh.
(4)

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)

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)

Mayur said:   3 years ago
@Anil Meghwal.

718 is not completely divisible by 8 hence option A is ruled out. B

But, options C & D both are correct.
(2)

Devesh Kinkar said:   6 months ago
To check if a number is divisible by 24, we use the divisibility rules of 8 and 3 because:
24 = 8×3.

Step 1: Check divisibility by 3.
A number is divisible by 3 if the sum of its digits is divisible by 3.

Step 2: Check divisibility by 8.
A number is divisible by 8 if its last three digits form a number that is divisible by 8.
(1)

Sapna Tonge said:   5 years ago
Why not option 1?
(1)

Madhav said:   6 years ago
537804 is also divisible by 24 (2, 3, 4).
(1)

Abica said:   6 years ago
3+5+7+1+8=24 also divisible then why not answer?
(1)

Ashwin said:   7 years ago
24 = 2 * 3 * 4 the given numbers compulsory divisible by 2, 3 and 4.

The option checks to all.
All option divisible 2.
The two option divisible 3 (537804 and 3125736).
The one option divisible 4 (3125736).
So 2, 3, 4 are divisible by 3125736. it is the correct answer.

Clear EXPLANATION:

2 divisible law.
Rule: If it ends with a 0, 2, 4, 6, or 8.

3 divisible law.
Rule: If the sum of the digits is a multiple of 3.
Number-----> Divisible -----> Reason
405-----> Yes-----> 4 + 0 + 5 = 9 (9 is a multiple of 3).
381-----> Yes-----> 3 + 8 + 1 = 12 (12 is a multiple of 3).
928-----> No -----> 9 + 2 + 8 = 19 (19 is not a multiple of 3).
4,616-----> No -----> 4 + 6 + 1 + 6 = 17 (17 is not a multiple of 3).

4 divisible law.
Rule: If the last two digits are a multiple of 4 (or if the last two digits are 00)
Number ----> Divisible ----> Reason
348 -----> Yes-----> 48 is a multiple of 4.
27,616 -----> Yes-----> 16 is a multiple of 4.
8,514 -----> No -----> 14 is not a multiple of 4.
722 -----> No-----> 22 is not a multiple of 4.
1,200-----> Yes -----> The last two digits are 00.

200 is a multiple of 4.

THANK YOU.
(1)


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