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2 years ago

7

How many quarts of a 50% solution of acid must be added to 20 quarts of a 20% solution of acid to obtain a mixture containing a

40% solution of acid?

1 answer:

Margaret [11]2 years ago

7 0

Suppose x quarts of the 50% solution
0.5x+0.2*20=0.4(x+20)
0.5x+4=0.4x+8
0.1x=4
x=40

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36 first-graders and 14 other students attended a school assembly. What percentage of the students at the assembly were first-gr

dimaraw [331]

Answer: 18%

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Then 36*50/100=18

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2 years ago

the minute hand of a clock is 5 inches long. what is the area of the circle, in square inches, created in a hand sweep in an hou

ira [324]

Solve the area of the whole circle since in an hour, the minute hand covers the whole clock
assuming that the minute hand reaches all the way out to the edge of the clock

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2 years ago

Answer if u love cats & dogs

eimsori [14]

Answer:

<em>(7, 5.25)</em> lies on the graph.

Step-by-step explanation:

We are given the following values

x = 4, 6, 8, 12 and corresponding y values are:

y = 3, 4.5, 6, 9

Let us consider two points (4, 6) and (6, 4.5) and try to find out the equation of line.

Equation of a line passing through two points $(x_1,y_1)$ and $(x_2,y_2)$ is given as:

$y=mx+c$

where m is the slope.

(x,y) are the coordinates from where the line passes.

c is the y intercept.

Here,

$x_{1} = 4\\x_{2} = 6\\y_{1} = 3\\y_{2} = 4.5$

Formula for slope is:

$m = \dfrac{y_{2}-y_{1}}{x_{2}-x_{1}}$

$m = \dfrac{4.5-3}{6-4}\\\Rightarrow m = \dfrac{1.5}{2}\\\Rightarrow m = \dfrac{3}{4}$

Now, the equation of line becomes:

$y=\dfrac{3}{4}x+c$

Putting the point (4,3) in the above equation to find <em>c</em>:

$3=\dfrac{3}{4}\times 4+c\\\Rightarrow 3=3+c\\\Rightarrow c =0$

So, final equation of given function is:

$y=\dfrac{3}{4}x$

OR

$4y=3x$

As per the given options, the point <em>(7, 5.25) </em>satisfies the equation.

So correct answer is $(7, 5.25)$ .

6 0

2 years ago

mina [271]

The answer is 44 and if he deposits it is 33 dollars:

11x4

1x4=4

1x4=4

So 11x4=44

And if he deposits 11 he will have 33

3 0

3 years ago

2/9 of the members are boys in a community service club. if there are 95 more girls than boys, how many girls are there in club?

KengaRu [80]

Answer:

133 girls

Step-by-step explanation:

Total members = x

Number of boys = $\frac{2}{9}x$

Number of girls = $\frac{2}{9}x +95$

Number of boys + Number of girls = total members

$\frac{2}{9}x+\frac{2}{9}x+95=x\\\\\frac{2}{9}x+\frac{2}{9}x=x -95\\\\\frac{2}{9}x+\frac{2}{9}x-x=-95\\\\\frac{4}{9}x-x = -95\\\\\frac{4}{9}x-\frac{9}{9}x = -95\\\\\frac{-5}{9}x=-95\\\\x = -95*\frac{9}{-5}\\\\x=19*9$

x = 171

Number of boys = $\frac{2}{9}*171$ = 2 * 19 = 38

Number of girls = 38 + 95 = 133

5 0

2 years ago