20.50 * 0.8 = $16.40
16.40 * 0.4 = $6.56
Final selling price = $6.56
W=wind
p + w=158...p=158-w
p-w=112...p=112+w
SO 158-w=112+w
46=2w
23=w
SO in conclusion you have the correct answer of wind being 23km/h while the plane is going 135 km/h
HOPE THIS HELPS!
Missing part of the question
Determine the number of handshakes, i, that will occur for each number of people, n, in a particular room. (people)
Answer:

Step-by-step explanation:
Given
For 5 people

Using the given instance of 5 people, the number of handshakes can be represented as:

The above sequence is an arithmetic sequence and the total number of handshakes is the sum of n terms of the sequence.

Where
--- The first term
--- The last term
So:


Answer:
Cartesian product
Step-by-step explanation:
The Cartesian product of two sets, X and Y, denoted by X × Y, is the set of all ordered pairs (x, y), where x is an element of X and y is an element of Y: 8 (2.4.1) X × Y = { (x, y) ∣ x ∈ X ∧ y ∈ Y } For example, if Children = { Peter, Mark, Mary }, and Parents = { Paul, Jane, Mark, Mary }, then