Total = 36oz
Amount of 18% solution = x
Amount of 9% solution = 36 - x
Using the fact that (amount of solution) * (percent HCl) = amount HCl we can set up an expression for the amount HCl in a mixture of 18% and 9% solutions with a total volume of 36oz.
Amount of HCl = x*0.18 + (36 - x)*0.09
If we divide this by the amount of solution we get percent HCl, and we have a target of 10% HCl. Now we have an equation to solve,
[x*0.18 + (36 - x)*0.09]/36 = 0.1
x*0.09 + 3.24 = 3.6
.09x = 0.36
x = 4
Therefore,
4 ounces of 18% HCl solution and 32 ounces of 9% HCl solution
Check:
[(4*.18) + (.09*32)]/36 = 0.1?
0.1 = 0.1 Yes.
9514 1404 393
Answer:
B (2 violet)
Step-by-step explanation:
Let the colors be represented by their first letter. Then the balances give rise to two equation:
o +y +b +v = r +g +b
o +y +v = g +v
Subtracting the second equation from the first gives ...
(o +y +b +v) -(o +y +v) = (r +g +b) -(g +v)
b = r +b -v
Adding v-b to both sides, we have ...
b +(v -b) = r +b -v +(v -b)
v = r
Multiplying this result by 2, we can match the final balance:
2r = 2v . . . . . . . choice B
Answer:
graph?
Step-by-step explanation:
The ground, the building, and the ladder form a right triangle, in which
the leaning ladder is the hypotenuse.
For the angle between the ladder and the ground, the 4-ft along the ground
is the side adjacent to the angle, and the 7-ft ladder is the hypotenuse.
(adjacent side) / (hypotenuse) = cosine of the angle.
Cosine(a) = 4/7 = 0.57143... (rounded)
Angle 'a' = <em>55.15 degrees</em> (rounded)
