February 2012

Example 01 | Age-related problem

Problem
Alfred is four times as old as his nephew Franco. 5 years ago, the sum of their ages is equal to the present age of Alfred. How old is each?
 

Example 02 | Age-related problem

Problem
The sum of the parents' ages is twice the sum of their children’s ages. Five years ago, the sum of the parents' ages was four times the sum of their children’s ages. In fifteen years, the sum of the parents' ages will be equal to the sum of their children’s ages. How many children were in the family?
 

Example 01 | Digit-related problem

Problem
The sum of the digits of a three-place number is 19. If the tens and units digits are interchanged the number is diminished by 27, and if the hundreds and tens digits are interchanged the number is increased by 180. What is the number?