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 4 of 6.
Priyanka P. said:
1 decade ago
hi..
the rule for division for 3 is the total of the given number should be divided by 3..
so when add 517x324=22 which can't be divided by 3, so we have to add 2, to make it dividable by 3.
after adding 2 it becomes 24 which can be divided by 3.
hope it helps u..
the rule for division for 3 is the total of the given number should be divided by 3..
so when add 517x324=22 which can't be divided by 3, so we have to add 2, to make it dividable by 3.
after adding 2 it becomes 24 which can be divided by 3.
hope it helps u..
Paavani said:
1 decade ago
I can't understand anyones explaination. If any one got this sum means please explain it clearly.
Janu said:
1 decade ago
Hi @Pavani..
If a number(for example take xyzpqr) is divisible by 3, then the sum(x+y+z+p+q+r) is also divisible by 3 and vice versa..
ex: 243 is divisible by 3
2+4+3=9 is also divisible by 3..
So if u want to check dat a number is divisible by 3 then it is enough to see whether the sum of digits in the number is divisible by 3..
If a number(for example take xyzpqr) is divisible by 3, then the sum(x+y+z+p+q+r) is also divisible by 3 and vice versa..
ex: 243 is divisible by 3
2+4+3=9 is also divisible by 3..
So if u want to check dat a number is divisible by 3 then it is enough to see whether the sum of digits in the number is divisible by 3..
Sonakshi said:
1 decade ago
Hi Janu! can we set this formula with every number?
Jay said:
1 decade ago
Let x
and chosen number form option
and 22 + 2 = 24
it.s divided by 8 so answer is 2
and chosen number form option
and 22 + 2 = 24
it.s divided by 8 so answer is 2
Divya said:
1 decade ago
How can we divide (22+x) by 3 ?
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
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