Question 1186096
<pre>
John           4m
Mark            m
Dan           2*4m
-------------------------
{{{4m-m=420}}}
</pre>
That could have been arranged differently, since the question was for how many stickers did Dan have.


{{{3m=420}}}

{{{m=(2*3*7*10)/3}}}

{{{m=cross(3*7*10)}}}
{{{m=2*7*10}}}

{{{cross(m=210)}}}
{{{highlight_green(m=140)}}}


For Dan, 1120 stickers