Answer:
There were 20 questions on the quiz
Step-by-step explanation:
In this question, we are concerned with knowing the number of questions on a quiz, given that Deana had a certain percentage after scoring an amount of marks.
We proceed as follows;
Let the number of questions on the quiz be X.
Now, she got 85% by making 3 incorrect choices. This means the percentage of questions she got incorrectly would be 100-85 = 15%
what we are saying is that it is just 15% of her questions that were wrong.
This mathematically;
15% of x = 3
15/100 * x = 3
15x = 3 * 100
15x = 300
x = 300/15
x = 20
Focus on triangles DFC and DFE:
- They are both right triangles because DF is perpendicular to EC
- DC=DE
- DF is a common side
So, the two triangles are congruent. It follows that CF=FE, and in particular
And since x=3, the length of EF is
A set of ordered pairs is called a relation. The set of all first components of the ordered pairs of a relation is the domain of the relation, and the set of all second components of the ordered pairs is the range of the relation. :)
