Answer:
1) Arithmetic since it decreases by 3 so, -3n + 38.
2) Arithmetic since it decreases by 20 each time, so -20n+17
Step-by-step explanation:
Let n be the total number of puffs. Now we can write:

Adding the fractional value of n, we get:

Simplifying and rearranging gives us:

Therefore we can simplify to get:

and finally

The fraction of the puff that are tuna is found from:
Answer:
The tree is 16.25 m tall.
Step-by-step explanation:
Attached is a diagram that better explains the problem.
From the diagram we see that the distance between the top of the tree and the line of sight of the observer is x.
To find the height of the tree, we need to first find x and then add it to the height of the observers line of sight from the ground.
Using SOHCAHTOA trigonometric function:
tan(20) = x/39.2
=> x = 39.2 * tan(20)
x = 39.2 * 0.364
x = 14.27m
Hence, the height of the tree is:
(14.27 + 1.98)m
16.25m
The tree is 16.25 m tall.