Answer:
Below
Step-by-step explanation:
9 
Basically you need to multiply the percent by the number.
The total area of the blades is the area of a triangle multiplied by 4.
We have then:

Where,
b: base of the blades
h: height of the blades
Substituting values we have:

Doing the calculation we have that the area of the blades is given by:

Answer:
The total area of the blades is:

Answer:
6 ways
Step-by-step explanation:
Given:
Books: Spanish, Maths and History textbooks (1 each)
Required
Determine the number of arrangements
In total, Nathan has 3 books.
The number of arrangements (n) is as follows:
The first book can be lined in 3 ways
The second book can be lined in 2 ways
The third book can be lined in 1 way
So,

