Question 194778
Let {{{f}}}= the Father's age now
Let {{{s}}}= the Son's age now
{{{f + 15}}}= the Father's age in {{{15}}} years
{{{s + 15}}}= the Son's age in {{{15}}} years
given:
(1) {{{f = 3s}}}
(2) {{{f + 15 = 2*(s + 15)}}}
Substitute (1) in (2)
{{{3s + 15 = 2*(s + 15)}}}
{{{3s + 15 = 2s + 30}}}
{{{s = 30 - 15}}}
{{{s = 15}}}
And
(1) {{{f = 3s}}}
{{{f = 3*15}}}
{{{f = 45}}}
The Father is 45 and the Son is 15
check:
(2) {{{f + 15 = 2*(s + 15)}}}
{{{45 + 15 = 2*(15 + 15)}}}
{{{60 = 60}}}
OK
It's not one of the choices,
so something isn't right.