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Question

How many Kgs of a 45% alloy must be added to 62kgs of a 60% allow to get a 50% alloy

Answer 1

Hi L,

The percents multiplied by their respective amounts equals the total amount times its percent.

 

For example, if you mix 10 grams of 100% alloy and 10 grams of 50% alloy, you would expect a total of 20 grams of 75% alloy and that's what you get:  10 x 1 + 10 x 0.5 = 20 x -.75

                                                     10 + 5 = 15

 

So now let's solve the question, understanding that the total amount of new alloy equals 62 kg + X, where X = the amount of 45% alloy.

 

0.45X + (0.60)(62) = (0.50)(62+X)

0.45X + 37.2 = 31 + 0.5X

6.2 = 0.05X

X = 125 Kg

 

Dan