Question 1129039
let son's age be {{{x}}}
if a man is 20 years older than his son, his age is {{{x+20}}}

if the ratio of the ages is {{{3:8}}}, than

{{{x/(x+20)=3/8}}}

{{{8x=3(x+20)}}}

{{{8x=3x+60}}}

{{{8x-3x=60}}}

{{{5x=60}}}

{{{x=60/5}}}

{{{highlight(x=12)}}}->son is {{{highlight(12)}}} years old


{{{x+20=32}}}->a man's age


check the ratio

{{{12/32=3/8}}}

{{{cross(12)3/cross(32)8=3/8}}}

{{{3/8=3/8}}}