Periodic Reporting for period 3 - ARiAT (Advanced Reasoning in Arithmetic Theories)

At school, many of us have encountered questions like this: "Agrandmother is 60 years old; her grandson is 4. In how many years willthe grandmother be 5 times as old as her grandson?" With some effort,we find the answer to be 10 years. Instead of trial-and-error, thistype of...