SOLUTION: How many liters each of a 35% acid solution and a 60% acid solution must be used to produce 70 liters of a 45% acid solution? (Round to two decimal places if necessary.)
Let x=a
Question 506102: How many liters each of a 35% acid solution and a 60% acid solution must be used to produce 70 liters of a 45% acid solution? (Round to two decimal places if necessary.)
Let x=amount of a 35% solution
let y=amount of a 60% solution
Which gives me x+y=70 and 0.35x+0.60y=31.5
What I don't understand is how they got 31.5 in the second equation.
Please help. Answer by solver91311(24713) (Show Source):
The amount of pure acid in the 35% solution is 0.35 times , the amount of pure acid in the 60% solution is 0.60 times , and the amount of pure acid in the final 45% solution is 0.45 times 70 since the total amount at the end is 70 liters. And .
By the way, I wouldn't introduce the second variable at all. You can save yourself a step by saying that represents the amount of 35% solution and then, since the total amount of solution is 70 liters, the amount of 60% solution has to be . That way my single equation for this problem comes out to:
John
My calculator said it, I believe it, that settles it
