Answer:
20 students
Step-by-step explanation:
If the class decreased by 15%, the students that she has now (17) represents a percentaje of:
100% - 15% = 85%
so<u> the 17 students are 85% of what she had</u>:
Students Percentage
17 ⇒ 85%
and we are looking for how many students she had 2 years ago, thus we are looking for the <u>100%</u> of students (the original number of studens). If we represent this number by x:
Students Percentage
17 ⇒ 85%
x ⇒ 100%
and we solve this problem using the <u>rule of three</u>: multiply the cross quantities on the table( 17 and 100) and then divide by the remaining amount (85):
x = 17*100/85
x = 1700/85
x=20
2 years ago she had 20 students
Answer:
I think it's -14
Step-by-step explanation:
x = 0 so the x won't be included but
-2 • x = -2x
-12 • x = -12x
-2x + (-)12x = -14
hope this helps :)
The molarity of the resulting solution is 3.99 × 10⁻⁴ M. The correct option is the third option 3.99 × 10⁻⁴ M
<h3>Molarity of a solution</h3>
From the question, we are to determine the molarity of the resulting solution
From the given information,
Number of moles = 5.99 × 10⁻⁶ mol
Volume = 1.50 × 10⁻² L
Using the formula,
Molarity = Number moles / Volume
∴ Molarity = (5.99 × 10⁻⁶) / (1.50 × 10⁻²)
Molarity = 3.99 × 10⁻⁴ M
Hence, the molarity of the resulting solution is 3.99 × 10⁻⁴ M. The correct option is the third option 3.99 × 10⁻⁴ M
Learn more on Calculating molarity here: brainly.com/question/23051191
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