The 53-year-old father has a son of 17 years. a) After how many years will the father be three times older than his son? b) Before how many years was the father 10 times older than the son?

1 Answer
Mar 29, 2018

A 53-year-old father has a son of 17 years.

a) After how many years will the father be three times older than his son?

Let the number of years be #x#.

#=>( 53+x)= 3(17+x)#

#=>53+x= 51+3x#

#=>2x=2#

#=>x=1#

Hence, after 1 year the father be three times older than his son.

b) Before how many years was the father 10 times older than the son?

Let the number of years be #x#.

#=>( 53-x)= 10(17-x)#

#=>53-x=170-10x#

#=> 9x = 117#

#=>x=13#

Hence, 13 years ago the father 10 times older than the son.