Answer:
. In other words, there number of girls is 
.
Step-by-step explanation:
The average of a number of measurements is equal to the sum of these measurements over the number of measurements.
.
Rewrite to obtain:
.
For this question:
.
.
Therefore:
.
On the other hand, there are 
boys and girls in total. Using the formula for average:
.
From the question, this average should be equal to 
. In other words:
.
Solve this equation for 
to obtain:
.
.
.
In other words, the number of girls here is .
X rays=E
Microwaves=A
Gamma rays=C
Radio waves=F
Infrared waves=D
Ultraviolet waves=B
Answer: 25.2361459992ft
This question can be solved by a trigonometric equation. Shadow formed when something with height like a tree, so it can be pictured as a vertical line. Shadow is a length of and can be pictured as a horizontal line.
In trigonometric, to find the vertical line length with horizontal line you need tan function. The sun angle will be used in the function, so the calculation would be: tan(31) x 42ft = 25.2361459992ft
I belive it is the second option!
