Divisibility Rules
Rule 1->
divisibility rule of 2,4,8,16,32--------------2^n.
2^1=2 ----------------------------------------last place always be even or 0.
2^2=4 ---------------------------------------- we have to see last two number and if it is divided by 4 then it is divisible by 4.(00)
2^3=8-------------------------------------------we have to see last three number and if it is divisible by 8 then it is divisible by 8.(000)
2^4=16------------------------------------------we have to see last four number and if it is divisible by 16 then it is divisible by 16.(0000)
2^5=32------------------------------------------we have to see last five number and if it is divisible by 32 then it is divisible by 32.(000000)
Examples based on 1st rule
Example1;whether 456445688989980 is divisible by 4.
solution:- Yes, it is divisible by 4 because last two number is divisible by 4.
Example 2:-Whether 734983876647366 is divisible by 32.
solution:- It is not divisible by 32 because last five number is not divisible by 32.
Rule 2->
Divisibility by 3 and 9.
Simply, Sum of numbers have to divide by 3 or 9.
Example:-4346645656454667 is divisible by 3?
Solution:- It is divisible by 3 because sum of this number is divisible by 3.
4+3+4+6+6+4+5+6+5+6+4+5+4+6+6+7
sum=81/3=27.
Rule 3->
Divisibility by 5.
last digit be 5 or 0.
Example:-32243545546576570 is divided by 5 ?
solution:-last number is 0 , so it is divided by 5.
Rule 4->
Divisibility by 11.
Example:-364876876 is divisible by 11?
solution:- 1)6+8+7+4+3----------------------------------------a
364876876
2)6+8+6+7---------------------------------------b
subtract b from a.
(6+8+7+4+3)-(6+8+6+7)=28-27=1
It is not divisible by 11 because mod is 1 so the number is only divisible by 11 when mod comes 0 and 11.
Rule 5:-
Divisibility by 99.
Example:-85643587 is divisible by 99?
solution:-85+64+35+87=271/99 it is not divided by 99.
