Question 106627
A father is 4 times as old as his son

Thus, if his son is {{{x}}} years old, then, his father is {{{4x}}} years old!


In twenty years, 20 yrs is added to their ages. Thus, if the father is {{{4x}}}, then in twenty  years,he will be {{{4x+2}}} years old! Similarly, his son will be {{{x+2}}} years old. However, in 20 years he will be twice as old as his son. So,

{{{4x+20=2(x+20)}}}
{{{4x+20=2x+40}}}
{{{4x+20-20=2x+40-20}}}
{{{4x+0=2x+20}}}
{{{4x=2x+20}}}
{{{4x-2x=2x-2x+20}}}
{{{2x=0+20}}}
{{{2x=20}}}
{{{2x/2=20/2}}}
{{{x=10}}}
{{{4x=40}}}

Therefore, the father is now 40 yrs old, while his son is 10 yrs old]


Power up,
HyperBrain!