Today was Catherine´s birthday. She turned 24. Catherine is twice as old as Ryan was when Catherine was as old as Ryan now. How old is Ryan now?..................
Test of divisiblity by 3
A given number is divisible by 3, if the sum of all the digits of the
number is divisible by 3.
Example:
7239 ==> 7+2+3+9 = 21 & 21 is divisible by 3,Therefore 7239 is divisible by 3.If you actually divide it and see, you get 2431
This rule can be applied for any number,however big it is.
One more big example:
2739546564610107 is divisible by 3, as the sum of the digits of this no is 66 which is divisible by 3.
Actual result 2739546564610107/3 is 913182188203369
Another example:
5677849 is not divisible by 3, as the sum of all the digits of the number is 46, and 46 is not divisible by 3.
