All categories

3 years ago

How many liters each of a 10% acid solution and a 80% acid solution must be used to produce 70 liters of a 65% acid solution?

Mathematics

1 answer:

stealth61 [152]3 years ago

4 0

Assume you need x liters 10% acid, y liters 80% acid

Then 10%x + 80%y = 65%*70, and x+y = 70

I get: x = 15, y = 55

You might be interested in

Square root of 119 with work

sammy [17]

√119 ≈ 10.908712115

6 0

3 years ago

Read 2 more answers

A square has side length of 9 in. If the area is doubled, what happens to the side length?

Alika [10]

Answer:

The side length is multiplied by $\sqrt{2}$

Step-by-step explanation:

we know that

The area of the original square is equal to

$A=9^{2}=81\ in^{2}$

If the area is doubled

then

The area of the larger square is

$A1=(2)81=162\ in^{2}$

Remember that

If two figures are similar, then the ratio of its areas is equal to the scale factor squared

Let

z ----> the scale factor

x ----> the area of the larger square

y ---> the area of the original square

$z^{2}=\frac{x}{y}$

we have

$x=162\ in\^{2}$

$y=81\ in\^{2}$

$z^{2}=\frac{162}{81}$

$z^{2}=2$

$z=\sqrt{2}$ ------> scale factor

therefore

The side length is multiplied by $\sqrt{2}$

7 0

3 years ago

A total of 50 raffle tickets are sold for a contest to win a car. If you purchase one ticket, what are your odds against winning

Darya [45]

Step-by-step explanation:

$odds \: against \: winning = \frac{1}{50} \\ \\$

3 0

3 years ago

Twenty five heat lamps are connected in a greenhouse so, that when one lamp fails, another takes over immediately (only one lamp

olga55 [171]

Answer:

P = 0.006

Step-by-step explanation:

Given

n = 25 Lamps

each with mean lifetime of 50 hours and standard deviation (SD) of 4 hours

Find probability that the lamp will be burning at end of 1300 hours period.

As we are not given that exact lamp, it means we have to find the probability where any of the lamp burning at the end of 1300 hours, So we have

Suppose i represents lamps

P (∑i from 1 to 25 ( $X_i$ > 1300)) = 1300

= P( $X^{'}$ > $\frac{1300}{25}$ ) where $X^{'}$ represents mean time of a single lamp

= P (Z> $\frac{52-50}{\frac{1}{\sqrt{25}}}$ ) Z is the standard normal distribution which can be found by using the formula

Z = Mean Time ( $X^{'}$ ) - Life time of each Lamp (50 hours)/ (SD/ $\sqrt{n}$ )

Z = (52-50)/(4/ $\sqrt{25}$ ) = 2.5

Now, P(Z>2.5) = 0.006 using the standard normal distribution table

Probability that a lamp will be burning at the end of 1300 hours period is 0.006

4 0

3 years ago

Omar works as a tutor for $15 an hour and as a waiter for $7 an hour. This month, he worked a combined total of 83 hours at his

Alborosie

Answer: $8t+581$

Step-by-step explanation:

<h3> The complete exercise is: "Omar works as a tutor for $15 an hour and as a waiter for $7 an hour. This month, he worked a combined total of 83 hours at his two jobs. Let "t" be the number of hours Omar worked as a tutor this month. Write an expression for the combined total dollar amount he earned this month."</h3><h3 />

Let be "t" the number of hours Omar worked as a tutor this month and "w" the number of hours Omar worked as a waiter this month.

Based on the data given in the exercise, you know that Omar worked a combined total of 83 hours this month.

Then, you can represent the number of hours he worked as a waiter this month with this equation:

$w=83-t$

Since he earns $15 per hour working has a tutor and $7 per hour working as a waiter, you can write the following expresion to represent the total money earned:

$15t+7w$

Since $w=83-t$ , you can substitute it into the expression and then simplify it in order to find the final expression that represents the total amount of money Omar earned this month.

This is:

$15t+7(83-t)=15t+581-7t=8t+581$

4 0

3 years ago