P= 13.6
Yyyyyyyyyyyyyyyooooooooouuuuuuuuuuurrrrrrrrrr WELCOME
Answer:
I believe it is 19.8
Step-by-step explanation:
well if 9 is the number then I would do
9.9 +
9.9
______
I get 19.8
Tell me if I am wrong :)
Let x be the volume (liters) of pure (at 100%) acid needed
Let y be the volume (liters) of the other acid (at 10%) needed
The final solution will be:
a) x+ y = 63 liters, AND their respective concentration in acid: is
100% x & 10% :y that will generate 63 liters at 20%
b) x +0.1 y = 63x 0.2 = 12.6
Let's solve this system of 2 equations:
x + y =63
x + 0.1 y = 12.6
Solving it will give you:
x= 7 liters at 100%
y = 56 liters at 10%
Well, if y is the notebook cost, well x+y=6.28, x+x+0.70=6.28, 2x=5.58, x=2.79.
The pencil box costs $2.79, while the notebook costs $3.49.
