How could the 22nd and the 24th U.S. Presidents have the same parents, but not be brothers?

Without changing the order of these numbers, how can they equal 100?

3 5 6 2 54 5

Each letter represents a different digit. Any digit can be used, but zero can never start a word. Given W = 2 and R = 6, what do the rest of the letters represent?

  TWO
+ TWO
------
 FOUR

Amir has three children. One is the same age as the first number in his age, another is the same age as the second number in his age, and the third is the same age as the sum of the two numbers in his age. None of the children are the same age and the total of everyone’s ages is 45. How old is Amir?