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
------------------------
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.
Well, you would use factorization for this, which would be MORE than 54 different codes! :D
1/3
2 of the books are math books and there are 6 books. This is 2/6. Now, divide both sides of the fraction by 2 to simplify it. This gives you a final answer of 1/3.
well, it's isosceles so use base angles theorem
the top angle is also x
90 + 2x = 180
subtract 90 from both sides
2x = 90
divide both sides by 2
x = 45 degrees
