<PRE><B>Question 1181173</B>
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First a standard algebraic solution....&lt;br&gt;
x kg at R30 per kg, plus (50-x) kg at R51 per kg, equals 50 kg at 42.60 per kg:&lt;br&gt;
{{{30(x)+51(50-x)=42.6(50)}}}
{{{30x+2550-51x=2130}}}
{{{-21x=-420}}}
{{{x=-420/-21=20}}}&lt;br&gt;
ANSWER: x=20kg of the Brazilian; 50-x=30kg of the Colombian.&lt;br&gt;
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And now an easy path to the answer if a formal algebraic solution is not required....&lt;br&gt;
Look at the three prices per kg on a number line -- 30, 42.60, and 51 -- and determine that 42.60 is 12.60/21 = 0.6 = 3/5 of the way from 30 to 51.&lt;br&gt;
That means 3/5 of the mixture should be the higher priced Colombian coffee.&lt;br&gt;
ANSWER: 3/5 of 50kg, or 30kg, of Colombian and the other 20kg of Brazilian.&lt;br&gt;
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The explanation in words makes this look like a longer path to the answer than the formal algebra.  However, the numbers you need to work with are much simpler with this informal solution method.&lt;br&gt;
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