Apharmacist needs 20 liters of a 2% saline solution. she has a 1% solution and a 5% solution available. how many liters of the 1% solution and how many liters of the 5% solution should she mix to make the 2% solution?

15 liters of 1% solution and 5 liters of 5% solution

Step-by-step explanation:

Let x liters of 1% solution needed and y liters of 5% solution needed to make this mixture.

We can say:

20(0.02) = x(0.01) + y(0.05)

0.4 = 0.01x + 0.05y

Also, we can write:

x + y = 20

x = 20 - y

We can put this into equation 1:

0.4 = 0.01x + 0.05y

0.4 = 0.01(20 - y) + 0.05y

0.4 = 0.2 - 0.01y + 0.05y

0.2 = 0.04y

y = 5 liters

Hence, x = 20 - 5 = 15 liters

We need,

15 liters of 1% solution and 5 liters of 5% solution

15%

step-by-step explanation:

use the table and count the number of guesses that has two correct answers.

the following are two correct answers

10010, 01100, 11000

a total of 3 numbers having 2 correct guesses out of 20 questions.

probability of getting 2 correct guesses = the number of questions getting 2 correct answers / total number of questions.

= 3/20

to convert it into percent multiply by 100, we get

= 3/20 * 100

= 15%

the answer is 15%

you.

mxb67

step-by-step explanation: