Grades 9-10 Video Solutions 2013-Level 9&10 Video Solutions 2013 problem16

Video Transcription

Question number 16, on John's birthday this year, he multiplied his age by his son's age and correctly obtained the answer 2013.  In which year was John born?  Let's look at the prime factorization of 2013 and see if we can come up with some possible ages for John and his son.  So 2013 factors as 3 times 11 times 61.  And so we're essentially done because John cannot be 3 nor 11 years old. He must be 61 years old. So John was born in the year, take 2013, subtract 61 and that gives us 1952.

Video Summary

Question number 16, on John's birthday this year, he multiplied his age by his son's age and correctly obtained the answer 2013. In which year was John born? Let's look at the prime factorization of 2013 and see if we can come up with some possible ages for John and his son. So 2013 factors as 3 times 11 times 61. And so we're essentially done because John cannot be 3 nor 11 years old. He must be 61 years old. So John was born in the year, take 2013, subtract 61 and that gives us 1952.

Keywords

John's birthday

age multiplication

prime factorization

year born

1952