Question 1031826
1.{{{M+F=17000}}}
.
.
.
{{{M/F=80/120=2/3}}}
2.{{{3M=2F}}}
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.
.
From 1,
{{{2M+2F=34000}}}
Substituting from 2,
{{{2M+3M=34000}}}
{{{5M=34000}}}
{{{M=6800}}}
So if each male asks a female the total going to the dance is,
{{{6800+6800=14600}}}
Leaving,
{{{17000-13600=3400}}}
3400 females without a dance date.