Aptitude - Numbers - Discussion
Discussion Forum : Numbers - General Questions (Q.No. 16)
16.
If the number 517*324 is completely divisible by 3, then the smallest whole number in the place of * will be:
Answer: Option
Explanation:
Sum of digits = (5 + 1 + 7 + x + 3 + 2 + 4) = (22 + x), which must be divisible by 3.
x = 2.
Discussion:
52 comments Page 2 of 6.
Ram said:
1 decade ago
Will this be applicable for all the numbers or only for 3.
Abhi said:
1 decade ago
@Divya.
We don't divide (22+x) by 3, it is an equation form. It means what you add in 22 so it can be divided by 3.
Ex
=> 22+x/3.
=> If we assume smallest number 0, 1 then we got sum is 22, 23 which is not divided by 3, so we add 3(x) , and we get 24 which is divisible by 3.
Hope you understand.
We don't divide (22+x) by 3, it is an equation form. It means what you add in 22 so it can be divided by 3.
Ex
=> 22+x/3.
=> If we assume smallest number 0, 1 then we got sum is 22, 23 which is not divided by 3, so we add 3(x) , and we get 24 which is divisible by 3.
Hope you understand.
Pavan said:
1 decade ago
@Ram, Sonakshi.
The adding of digits to check divisibility can be done only for 3 which is rule for test of divisibility for 3.
Similarly,To check divisibility of 9 the sum of digits should be 9.
Ex: 45 => 4+5=9 . So 45 is divisible by 9.
Each digit has its own Divisibility rule to check whether it exactly divides the given or not.
The adding of digits to check divisibility can be done only for 3 which is rule for test of divisibility for 3.
Similarly,To check divisibility of 9 the sum of digits should be 9.
Ex: 45 => 4+5=9 . So 45 is divisible by 9.
Each digit has its own Divisibility rule to check whether it exactly divides the given or not.
Vidyadhar said:
1 decade ago
(5 + 1 + 7 + x + 3 + 2 + 4)
=22+x means
22/3 Remain 1
Then
3-1 = 2
Answer is 2
=22+x means
22/3 Remain 1
Then
3-1 = 2
Answer is 2
Krish said:
1 decade ago
We can't understand clearly give me a correct notes.
Prajith said:
1 decade ago
Is this method is only applicable when the divisor is 3?
Sudharshan said:
1 decade ago
Can you send anybody divisible rules for remaining numbers 7, 6, 8?
Nithya said:
1 decade ago
517*324 its divided by 3.
5+1+7+X+3+2+4 = 22+X.
X = 0, 1, 2, 3, .
22+0 = 22. Its not divided by three.
22+1 = 23. Its not divided by three.
22+2 = 24(8*3) = 24 is divided by three.
So, the x value is 2. The two will be added. So the number is divided by three. So the answer is three.
5+1+7+X+3+2+4 = 22+X.
X = 0, 1, 2, 3, .
22+0 = 22. Its not divided by three.
22+1 = 23. Its not divided by three.
22+2 = 24(8*3) = 24 is divided by three.
So, the x value is 2. The two will be added. So the number is divided by three. So the answer is three.
Shailu said:
1 decade ago
Just all see @Nikitha comment she describes it well.
Ramesh nigam said:
10 years ago
Can we apply this trick on all numbers, or its just applicable on number 3?
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