SOLUTION: 9 Kg. of gold which is 80% pure is mixed with an unknown amount of gold which is 75% pure. The purity of the resulting mixture is 78%. What quantity of the second type of gold was
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Question 1147676: 9 Kg. of gold which is 80% pure is mixed with an unknown amount of gold which is 75% pure. The purity of the resulting mixture is 78%. What quantity of the second type of gold was added?
Your basic equation is THIS :
0.8*9 + 0.75*x = 0.78*(x+9)
From it, express x and calculate
x = = 4.5.
ANSWER. 4.5 kg of the second alloy should be added.
Solved.
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It is a standard and typical mixture word problem.
You will find there ALL TYPICAL mixture problems with different methods of solutions,
explained at different levels of detalization, from very detailed to very short.
A convenient place to quickly observe these lessons from a "bird flight height" (a top view) is the last lesson in the list.
Read them and become an expert in solution mixture word problems.
