What is 672,831 rounded to hundred thousand

A pharmacist has an 18% alcohol solution and a 40% alcohol solution. How much of each should he mix together to make 10 liters o

ladessa [460]

X = amount of the 18% solution

y = amount of the 40% solution

we know the 18% solution has only 18% of alcohol, the rest is maybe water or something, now, how many liters is 18%? well, 18% of anything is just (18/100) * anything, so, 18% of x is just (18/100) *x or 0.18x, and that's how many liters are there.

likewise, how many liters are there in the 40% solution? well, (40/100) * y, or 0.4y, that many.

we know the mixture has to yield 10 liters at 20% alcohol, how many liters of only alcohol is that? well, (20/100) * 10, or 2 liters.

$\bf \begin{array}{lccclll}
&\stackrel{liters}{amount}&\stackrel{alcohol~\%}{quantity}&\stackrel{liters}{alcohol}\\
&------&------&------\\
\textit{18\% solution}&x&0.18&0.18x\\
\textit{40\% solution}&y&0.40&0.4y\\
------&------&------&------\\
mixture&10&0.20&2
\end{array}$

$\bf \begin{cases}
x+y=10\implies \boxed{y}=10-x\\
0.18x+0.4y=2\\
----------\\
0.18x+0.4\left( \boxed{10-x} \right)=2
\end{cases}
\\\\\\
0.18x-0.4x+4=2\implies -0.22x=-2
\\\\\\
x=\cfrac{-2}{-0.22}\implies x=\cfrac{100}{11}\implies x=9\frac{1}{11}$

how much of the 40% solution? well y = 10 - x

3 0

3 years ago

Find the missing measurement round your answer to the nearest tenth

yarga [219]

Answer:

5

Step-by-step explanation:

Let, the unknown side be x.

1/2 × 6.6m × xm = 16.5m²

or, x= 33/6.6

x= 5

4 0

3 years ago

A circle with circumference 20 has an arc with 72 degree central angle what is length of the arc

Debora [2.8K]

Answer:

Step-by-step explanation:

Look at the picture.

At the beginning we have to calculate what part of the angle 360° is the given angle 75°.

$\dfrac{75}{360}=75:360=0.2$

The same part of the circumference of the circle is the arc defined by this central angle.

The circumference C = 20.

Therefore

$x=0.2\cdot20=4$

4 0

2 years ago

How do I find the value of the missing sides and angles

Zarrin [17]

That is a 30 60 90 triangle.
Read about those here: http://www.1728.org/trig2.htm

4 0

2 years ago

Use the pythagorean theorem to find the missing side. Round your answer to the nearest tenth

Monica [59]

Answer:

x=14.02

Step-by-step explanation:

Use b= $\sqrt{c^2-a^2}$ to solve for the missing side in the triangle. You will get a rounded answer of 8.49. Then you multiply that by 2 and subtract that value from 31. Then that will be your answer.

5 0

2 years ago