Question 1167890
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Gerald who is twelve years old is two times as old as his sister Jane.
How old was Gerald when he was three times as old as Jane
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x, Jane
y, Gerald
{{{system(y=12,x=6)}}}---------simply what the description gives.



When Gerald was 3 times as old as jane,  p years ago.
{{{12-p=3(6-p)}}}
-
{{{12-p=18-3p}}}
{{{-p=6-3p}}}
{{{3p-p=6}}}
{{{2p=6}}}
{{{highlight_green(p=3)}}}------three years ago.


Gerald WAS {{{highlight(highlight(9))}}} years old.