Answer:
The probability is 
Step-by-step explanation:
We can divide the amount of favourable cases by the total amount of cases.
The total amount of cases is the total amount of ways to put 8 rooks on a chessboard. Since a chessboard has 64 squares, this number is the combinatorial number of 64 with 8, 
For a favourable case, you need one rook on each column, and for each column the correspondent rook should be in a diferent row than the rest of the rooks. A favourable case can be represented by a bijective function 
with A = {1,2,3,4,5,6,7,8}. f(i) = j represents that the rook located in the column i is located in the row j.
Thus, the total of favourable cases is equal to the total amount of bijective functions between a set of 8 elements. This amount is 8!, because we have 8 possibilities for the first column, 7 for the second one, 6 on the third one, and so on.
We can conclude that the probability for 8 rooks not being able to capture themselves is
Answer:
14
Step-by-step explanation:
im different
<span>Chris' average speed is 3.5mph:
Lets take Chris' brother speed = B
then Chris speed = (B+ 1) mph-------given in the question
and:
The average speed for covering 18 miles= chris' average speed + his brother's
average speed = (B+ 1) + B
since Speed = Distance covered / time taken
then average speed for 18 miles can also be found by: 18 miles/3 hours = 6 miles per hour
then we have; (B+ 1) + B = 6mph
(B +1) = (6-B)
B+B = 6-1=5
2B=5
B=5/2=2.5 mph (this is Chris' brother average speed)
Hence Chris' average speed is = B+1= 2.5+1= 3.5mph</span>
Answer:
12:50 PM.
Step-by-step explanation:
We have been given that Craig’s school has 4 lessons in the morning and lesson 1 starts at 8:35. Each lesson is 60 minutes long. There is a break of 15 minutes between lesson 2 and 3.
We can see that lesson 1 will end at 9:35 AM and second lesson will end at 10:35 AM.
We have been also given that there is a break for 15 minutes between lesson 2 and 3. So third lesson will start at 10:50 AM as lunch break will end at 10:50 AM.
Third lesson will end 60 minutes after 10:50 AM that is 11:50 AM and fourth lesson will end 60 minutes after 11:50 AM that is 12:50 PM.
Therefore, 4th lesson will end at 12:50 PM.
<span>What is the area of a regular octagon with a side length of 4.6 meters and a length from the center to a vertex of 6 meters?
Good Morning
The Correct Answer is c) 101.2
Hope I Helped
-Nullgaming650
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