He will mix some 20% solution and some 70% solution to make 60% solution.
Let x = number of liters of 20% solution.
Let y = number of liters of 70% solution.
He wants to make 50 liters of 60% solution, so
x + y = 50 First Equation
The amount of acid in x amount of 20% solution is 20% of x, or 0.2x
The amount of acid in y amount of 70% solution is 70% of y, or 0.7y
The amount of acid in 50 liters of 60% solution is 60% of 50 liters, or 0.6 * 50 = 30
Now we add the amounts of acid.
0.2x + 0.7y = 30 Second Equation
x + y = 50
0.2x + 0.7y = 30
-0.2x - 0.2y = -10
0.2x + 0.7y = 30
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0.5y = 20
y = 40
x + y = 50
x + 40 = 50
x = 10
Answer: He needs 10 liters of 20% solution and 40 liters of 70% solution.
Let x be the number of MP3 players TechWiz sold last week.
If TechWiz sold in total 130 MP3 and DVD players, then it sold (130-x) DVD players.
1. TechWiz Electronics makes a profit of $35 for each MP3 player sold, then it makes a profit $35x for x MP3 players sold.
2. TechWiz Electronics makes a profit of $18 for each DVD player sold , then it makes a profit $18(130-x) for (130-x) DVD players sold.
3. An expression for the combined total profit (in dollars) TechWiz made from MP3 and DVD players last week is
35x+18(130-x).
You can simplify it:
35x+2,340-18x=17x+2,340
Answer: 35x+18(130-x) or 17x+2,340
Answer: 0.0485610791367
Step-by-step explanation:
