Question 838203
Let {{{A}}} and {{{B}}} be the numbers.
{{{A/B=2/3}}}
1.{{{3A=2B}}}
and
{{{A+B=420}}}
Multiply eq. 2 by {{{3}}} and substitute from eq. 1,
{{{3A+3B=1260}}}
{{{(2B)+3B=1260}}}
{{{5B=1260}}}
{{{B=252}}}
Then from eq. 1,
{{{3A=2(252)}}}
{{{A=504/3}}}
{{{A=168}}}