Divisibility Rule of 9


 
 
Concept Explanation
 

Divisibility Rule of 9

Divisibility Rule of 9:

A number is divisible by 9, if the sum of its digits is divisible by 9.

Justification:

Let us first consider case of a two digit number:

 n=overline{ab} be a two digit number. Then, n can be written as

         n = 10a + b, where b is units digit of n.

Rightarrow    n = 9a + a + b

Rightarrow    n = a multiple of 9 + ( a + b )

Rightarrow    n is a multiple of 9, if ( a + b ) is a multiple of 9

Thus, a two digit number is divisible by 9, if the sum of its digits is divisible by 9.

.... (More Text Available, Login?)
Sample Questions
(More Questions for each concept available in Login)
Question : 1

if the three digit numbers 6 y 8 is divisible by 9 then the value of y is

Right Option : D
View Explanation
Explanation
Question : 2

Consider the following statements and choose the correst option (s) for them.

I. A number divisible by 3 is also divisible by 9.

II. A number divisible by 3 and by 9, if the sum of all its digits can be divided by 3 and by 9, respectively.

Right Option : B
View Explanation
Explanation
Question : 3

Which of the following is  not divisble by 9 ?

Right Option : C
View Explanation
Explanation
Chapters
Content / Category
Class / Course
 
 


Students / Parents Reviews [20]