Decimal fraction for competitive exam

Divisibility Rules

• If the end digit of any number is Zero or Even Number then number can easily Divisible by 2. Example: 4587952/2 = 2293976.

• If the Sum of all numbers is divisible by 3 then the number is divisible by 3. Example:(8+6+1) = 15 and 15 is divisible by 3, So the 861 is divisible by 3. Some more Example: 22104/3 = 7368. (2+2+1+0+4) = 9. 9/3 = 3, So 22104 divisible by 3.

• The number is Divisible by 4 when the end of two digit is divisible by 4 or end of two digit is Zero. Example: 85736 = 21434. (End two digit divisible by 4). 98300 = 24575 (End of both digit is Zero).

• The number is end with Zero or 5 Then the number is divisible by 5. Example: 7775/5 = 1555 (End digit is 5), 3390/5 = 678 (End digit is 0).

• The number is divisible by 6 when the number is divisible by 3 and 2. So both the condition should be satisfied by Rule 3 and 2 otherwise number will be not divisible by 6. 5844/6 = 974 (Both condition are satisfied).

•  Three end digit of number if divisible by 8 and if the last three digit is Zero then the number is also divisible by 8. Example:224256/8=28032 here the last digit 256 is divisible by 8 so the total number should be divisible by 8. 92045000/8=11505625.last three digit is Zero so the number is divisible by 8.

• All digits sum of a number if divisible by 9 then the number is divisible by 9.Example: 9522:(9+5+2+2)=18 that is divisible by 9 so the number 9522/9=1058.

• The number is divisible by 10 if the number is end with Zero then the number divisible by 10. Example: 4790/10=479 and 1250/10=125 this two numbers are end with Zero that why it is divisible by 10.

• Using 11 a number is divisible if difference sum of Even places and sum of odd places is Zero so divisible by 11. Example: 1236431460/11=112402860. (1+3+4+1+6)(odd places)-(2+6+3+4+0)(Even places)=0 and sum of odd and Even digit is equal so the number is divisible by 11.

• We can write 15 as (5×3) so if a number is divisible by 5 and 3 then the number is divisible by 15.