A metallurgist has an alloy with 15% titanium and an alloy with 20% titanium. He needs 100 grams of an alloy with 17% titanium. How much of each alloy should be mixed to attain the 100 grams of alloy with 71% titanium?

Ok so the answer in here is 60 grams of the alloy with 10% of titanium needed and 40 grams of the alloy with 25% of titanium are needed.

Let me explain it to you

let x = grams of alloy A and y = grams of alloy B.

x + y = 100 which is mass of A + mass of B = 100

and 0.15x + 0.20y = 0.17*100

which is fractionA*massA + fractionB*massB = fractionTotal*massTotal

0.15 (100 - y) + 0.20y = 17

15 - 0.15y + 0.20y = 17

0.05y = 2 y = 40 grams

x = 100 - y = 60 grams