A grocer mixes together some cashews costing $8 per kilogram with some Brazil nuts costing $10 per kilogram. The grocer sold 12 kilograms of the mixture for $8.50 per kilogram. How many kilograms of cashews were in the mixture in the grocer sold?
Let the kilograms of cashews = x
Then...the kilograms of Brazil nuts = 12 -x
And we have that.......
Quantity of kilos of cashews * price per kilogram + quantity of kilos of Brazil nuts * price per kilogram = 12 kilo mixture at 8.50 per kilogram
x * 8 + (12 - x) * 10 = 12 * 8.50 simplify
8x + 120 - 10x = 102
-2x + 120 = 102 subtract 120 from each side
-2x = -18 divide both sides by -2
x = 9 kilos of cashews