Total number of ways to make a pair:
The first player can be any one of 7 . For each of those . . .
The opponent can be any one of the remaining 6 .
Total ways to make a pair = 7 x 6 = 42 ways .
BUT ... every pair can be made in two ways ... A vs B or B vs A .
So 42 'ways' make only (42/2) = 21 different pairs.
If every pair plays 2 matches, then (21 x 2) = <em><u>42 total matches</u></em> will be played.
Now, is that an elegant solution or what !
For this case we have the following equation:

Where, we have the following variables:
x: time in seconds
y: speed in feet per seconds
For the initial velocity, we evaluate x = 0 in the given equation:

Therefore, the initial speed is 12 feet per second.
Answer:
The particle's initially velocity is 12.
Answer:
x = 3.76 ft
Step-by-step explanation:
To find the missing side, "x", solve using proportions.
In similar polygons, the 'new' polygon was created by multiplying every side of the 'old' polygon by the same number. Every side was multiply by the <u>scale factor</u>, "k", which tells you how much a polygon grew (k>1) or shrunk (0<k<1).
Therefore, if you divided the pairs of corresponding sides, they would be equal.
From the diagram, you can tell that the following sides correspond:
CB ~ GF
AB ~ EF
<u>Use the proportion</u>

Substitute values from diagram
Multiply both sides by 6 ft
"x" is isolated. Multiply fraction by combining into numerator
Solved numerator. Divide for decimal answer.

The value of 'x' is 3.76 ft.
The decimal for 77/200 is 0.385
The answer is a)
Let me know if you need an explanation