<PRE><B>Question 286292</B>
s+n=3000  s=3000-n
3s+5n=10000
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3(3000-n)+5n=10000
9000-3n+5n=10000
2n=1000
n=500
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s+500=3000
s=2500
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3*2500+5*500=10000</PRE>