We are choosing 2
2
r
shoes. How many ways are there to avoid a pair? The pairs represented in our sample can be chosen in (2)
(
n
2
r
)
ways. From each chosen pair, we can choose the left shoe or the right shoe. There are 22
2
2
r
ways to do this. So of the (22)
(
2
n
2
r
)
equally likely ways to choose 2
2
r
shoes, (2)22
(
n
2
r
)
2
2
r
are "favourable."
Another way: A perhaps more natural way to attack the problem is to imagine choosing the shoes one at a time. The probability that the second shoe chosen does not match the first is 2−22−1
2
n
−
2
2
n
−
1
. Given that this has happened, the probability the next shoe does not match either of the first two is 2−42−2
2
n
−
4
2
n
−
2
. Given that there is no match so far, the probability the next shoe does not match any of the first three is 2−62−3
2
n
−
6
2
n
−
3
. Continue. We get a product, which looks a little nicer if we start it with the term 22
2
n
2
n
. So an answer is
22⋅2−22−1⋅2−42−2⋅2−62−3⋯2−4+22−2+1.
2
n
2
n
⋅
2
n
−
2
2
n
−
1
⋅
2
n
−
4
2
n
−
2
⋅
2
n
−
6
2
n
−
3
⋯
2
n
−
4
r
+
2
2
n
−
2
r
+
1
.
This can be expressed more compactly in various ways.
It's not rigid because dilations (scale factor not equal to 1) change the length of the segments, or the distances between the points. You'll get a similar figure but it won't be congruent. For example, if the scale factor is 3, then the distances will be three times as large; or the lengths will be 3 times as long.
To be "rigid", the lengths must be kept the same. In contrast, a reflection is rigid because the distances are kept the same. The only thing changing is the orientation (clockwise to counter-clockwise, or vice versa).
8: 2 2 2
10: 2 5
GCF: 2
The greatest common factor is 2
54x = 864
A. x = 17 → 54(17) = 918 ≠ 864
B. x = 2 → 54(2) = 108 ≠ 864
C. x = 19 → 54(19) = 1,026 ≠ 864
<h3>Answer: D. none of these</h3>
Solution
54x = 864 <em>divide both sides by 54</em>
x = 16
Answer:
0.002206 pounds in a gram
Step-by-step explanation:
2.206/1000 = 0.002206
