Question 342360
please help me solve this: A father is four times as old as his son. In six years time,their combined ages will be 57. How old is the father now?


Let father's age be F years


Since the father is four times as old as the son, then the son's age is {{{1/4}}} the father's age, or {{{(1/4)F}}} years


In six year's time, the father will be (F + 6) years-old, and the son: {{{(1/4)F + 6}}}


Also, since in 6 year's time, their combined ages will be 57, then we'll have: 


{{{F + 6 + (1/4)F + 6 = 57}}}


Multiplying the equation by it's LCD, 4, we get: 


4F + 24 + F + 24 = 228 


5F + 48 = 228


5F = 228 - 48


5F = 180


F, or father's age is: {{{180/5}}} or {{{highlight_green(36)}}} years.