Answer:
The height of the lighthouse is 
Step-by-step explanation:
Let
h -----> the height of the lighthouse
we know that
The tangent of angle of 68 degrees is equal to divide the height of the lighthouse by the horizontal distance from the buoy to the base of lighthouse
so

Solve for h

A box of donuts would cost: b = 3.84 + 0.18f
First, we have to find the total cost of the donuts.
12 x 0.32 = 3.84
Next, we need to determine the cost of the box. However, we don't know the surface area, just the cost per foot. We can multiply the number of square feet of the box by $0.18 to find the cost.
So our equation could be: b = 3.84 + 0.18f (where f is the surface area of the box in square feet)
Answer:
C AND D
Step-by-step explanation:
it is a rational and real number
The series 7 + 16 + 25 +34 +43 +52 + 61 is an illusration of arithmetic series
The sigma notation of the series is: 
<h3>How to write the series in sigma notation?</h3>
The series is given as:
7 + 16 + 25 +34 +43 +52 + 61
The above series is an arithmetic series, with the following parameters
- First term, a = 7
- Common difference, d = 9
- Number of terms, n = 7
Start by calculating the nth term using:
a(n) = a + (n - 1) * d
This gives
a(n) = 7 + (n - 1) * 9
Evaluate the product
a(n) = 7 - 9 + 9n
Evaluate the difference
a(n) = 9n - 2
So, the sigma notation is:

Read more about arithmetic series at:
brainly.com/question/6561461