Aptitude - Numbers - Discussion
Discussion Forum : Numbers - General Questions (Q.No. 21)
21.
Which of the following number is divisible by 24 ?
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.
Abica said:
6 years ago
3+5+7+1+8=24 also divisible then why not answer?
(1)
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).
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).
Muthyal said:
6 years ago
What is co-prime?
Raj said:
7 years ago
Why are we taking 3 and 8 only and not 4, 6 or 12, 2?
(1)
Rohit kumar said:
7 years ago
35718 = 3*8=24/24 divisible.
63810= 3*8 = 24 /24 divisible.
537804 = 3*8 = 24 / 24 divisible.
3125736 = 3 available but 8 is not available whose it can make 24, if given in question no is 24 will be not divisible therefore answer is 3125736.
63810= 3*8 = 24 /24 divisible.
537804 = 3*8 = 24 / 24 divisible.
3125736 = 3 available but 8 is not available whose it can make 24, if given in question no is 24 will be not divisible therefore answer is 3125736.
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.
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)
Sia said:
7 years ago
Why there is a division of 738 only?
Alli said:
7 years ago
A is also divisible by 24, 3+5+7+1+8.
Anand said:
8 years ago
24=3*8 why we can take?
24=4*6 why can't take?
24=4*6 why can't take?
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.
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.
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