Answer:
Tina can select and answer the essay questions on her test in 35 ways.
Step-by-step explanation:
The order in which she chooses the questions is not important. For example, choosing questions 1, 3 and 7 is the same as choosing 7, 3 and 1. So we use the combinations formula to solve this question.
Combinations formula:
is the number of different combinations of x objects from a set of n elements, given by the following formula.

In this question:
Three questions from a set of 7. So

Tina can select and answer the essay questions on her test in 35 ways.
First you need to find the area of the whole circle.

The radius is given as 10, so just insert 10 into the equation of the area of a circle equation.

Putting

after the 100 because that is what is commonly done.
Because the circle is then being split into 4 equal sections, we need to find 1/4 of the area of the whole circle to find the area of one of these sections.
Since the area of the whole circle is

then we just divide that by 4,
leaving us with 25

and that is our final answer
If this is a 30, 60, 90 triangle, which I think it is, it would b 4
Answer:
7.2*10^3.
7,200 in scientific notation, is 7.2*10^3