Question 1062824
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<pre>
500 = 

0*50 + 25*20   (#1)
2*50 + 20*20   (#2)
4*50 + 15*20   (#3)
6*50 + 10*20   (#4)
8*50 +  5*20   (#5)
10*50 + 0*20   (#6)
</pre>