All categories

3 years ago

How much pure alcohol must be added to 400 ml of a 15% solution to make its strength 32%

1 answer:

6 0

Quantity of alcohol =400*15/100 = 60ml
x is <span>pure alcohol which must be added : (x + 60)/(x + 400) = 32/100
100x + 6000 = 32x + 12800 => 68x = 6800 => x = 100
100ml pure alcohol must be added

</span>

You might be interested in

How do you find percent of a number mentally

olga55 [171]

It isn't easy really but you can always divide the number out. For example 50% of 200 is 100 by dividing 200 by 2 or 25% of 100 is 25 by dividing 100 by 4 since 25% is equivalent to 1/4

5 0

3 years ago

Read 2 more answers

Write an equation in slope-intercept form for the following line:<br><br> (-14,1) and (13,-2)

alex41 [277]

Answer:

$\large \boxed{y = - \frac{1}{9} x - \frac{5}{9} }$

Step-by-step explanation:

In order to find an equation of a line with two given ordered pairs. We have to find a slope first which we can do by using the formula below.

$\large \boxed{m = \frac{y_2 - y_1}{x_2 - x_1} }$

m-term is defined as slope in y = mx+b form which is slope-intercept form.

Now we substitute these ordered pairs (x, y) in the formula.

$\large{m = \frac{1 - ( - 2)}{ -14 - 13} } \\ \large{m = \frac{1 + 2}{ - 27} } \\ \large{m = \frac{3}{ - 27} = - \frac{1}{9} }$

After we calculate for slope, we substitute m-value in slope-intercept form. The slope-intercept form is

$\large \boxed{y = mx + b}$

We already know m-value as we substitute it.

$\large{y = - \frac{1}{9} x + b}$

We are not done yet because we need to find the b-term which is our y-intercept. (Note that m-term is slope while b-term is y-intercept)

We can find the y-intercept by substituting either (-14,1) or (13,-2) in the equation. I will be using (13,-2) to substitute in the equation.

$\large{y = - \frac{1}{9} x + b} \\ \large{ - 2 = - \frac{1}{9} (13) + b} \\ \large{ - 2 = - \frac{13}{9} + b} \\ \large{ - 2 + \frac{13}{9} = b} \\ \large{ - \frac{5}{9} = b}$

Finally, we know b-value. Then we substitute it in our equation.

$\large{y = - \frac{1}{9} x + b} \\ \large{y = - \frac{1}{9} x - \frac{5}{9} }$

4 0

2 years ago

What does the pH of a solution represent?

lana [24]

Answer:

D. The pH indicates how acidic or basic a solution is.

Step-by-step explanation:

The range goes from 0 to 14, with 7 being neutral.

7 0

2 years ago

Help I am being timed

Levart [38]

Answer:

Let us say x is a real number and z = a + ib is complex

|x| > 0

|z| = |a + ib| = square-root (a^2 + b^2)

Step-by-step explanation:

|x| > 0 the absolute value of a real number is a nonnegative real number

The |a + ib| = square-root of the sum of the squares of the real components of the complex number

3 0

2 years ago

Mr smith earns $75 a day plus $35 for each car he sells if e is the amount he earned and c is the number of cars he sold which e

jeka94

Answer:

110

Step-by-step explanation:

So if add 75 + 35 you will get the number 110

Really hoped this helped

6 0

3 years ago