How many units of a 10% solution are needed to prepare 500 units of a 2% solution?

1 answer:

8 0

First find how many units of solution there is:

500* 2% = 500(.02) = 10 units

You need 10 units of solution in 'x' units of a 10% solution.

x*10% = 0.1x = 10 units -----> x = 10/0.1 = 100

100 units are needed

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the width of a rectangle is 8 feet and the diagnal length of the rectangle is 13 feet which measurement is closest to the length

____ [38]

Answer:

Well the whole answer is 10.246950 smth smth but I don’t have the multiple choices so your gonna have to round yourself

Step-by-step explanation:

Okay so you have a weigh of 8 and a diagonal of 13.

If you look, theres a triangle there. One side has 8 and the diagonal that was cut forms a 13. So we have a leg and a hypotnuse. To find the other leg (length) just follow the Pythagorean theroum and solve for b or a.

Pythagorean theroum: a^2+b^2=c^2

Now subsitute c for 13 since its the hypotnuse and a or b as 8 but only one.

In this case I’m substituting a for 8.

8^2+b^2=13^2

Solve the squares

64+b^2= 169

Isolate the b

b^2=105

Now square root 105

√105 will give the answer above on a normal calculator but if you have to round, I don’t know what place but you can round.

7 0

2 years ago

Please help Explanation will be appreciated thanks,

Genrish500 [490]

Answer: A; 6.3%

Step-by-step explanation:

Problem 1

For the first problem, we first want to find y so that we can plug it into the expression.

We can use elimination method for the system of equations to solve.

3x+3y=21

3x-y=5

We subtract both equations to eliminate x.

4y=16 [divide both sides by 4]

y=4

Now that we know y, we can plug it into the expression.

$\frac{4}{2} -3$ [divide]

$2-3$ [subtract]

$-1$

We know that the answer is A.

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Problem 2

For the second problem, we need to know how to calculate percent error. The formula for precent error is $\frac{|measured-exact|}{exact} *100%$ . We know that the exact value is 80 because the buyer was supposed to given 80. 75 is the measured value because that was what the buyer was given.