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 11
A given number is divisible by 11,if the difference between sum of odd digits & sum of even digits is 0 or divisible by 11.
Example:
946 ==> Some of odd digits is 9 + 6 = 15 and even digit is 4; Difference between 15 & 4 is 11 which is divisible by 11
This rule can be applied for any number,however big it is.
One more big example:
Let us find whether 30135012210713110 is divisible by 11
Sum of Odd digits:--3+1+5+1+2+0+1+1 = 14 Sum of even digits:-0+3+0+2+1+7+1 = 14
Difference between sum of odd digits and even digits is 0;
Actual result is : 273954656461010
Another example:
53672849 is not divisible by 11.
Sum of odd digits: 5+6+2+4 = 17
Sum of even digits: 5+7+8+9 = 29
Difference is : 12,which is not divisible by 11.Therefore 53672849 is not divisible by 11.
