Answer:

Step-by-step explanation:
There are only 2 solutions for none of the rooks can capture any of the other rooks: only if they are laid out in either of the 2 diagonal of the chess board
The number of possible combination for the rock to laid out in 8x8 (64 slots) chess board
possible combination
So the probability is pretty thin

Let T represent the fifth test score. The average is the sum of scores divided by their number.
... 82 = (83 +75 +93 +67 +T)/5
... 410 = 318 +T . . . . . . . multiply by 5
... 92 = T . . . . . . . . . . . . subtract 318
The fifth score was 92.
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One of the ways I like to work problems like these is to add the differences from the mean. Those are ...
1, -7, 11, -15
so their sum is -10.
The final score must be 10 above the mean in order for this total to be zero. 10 above the mean is 92.
<span>(a) $7.04
(b) 704/1599
(c) 0.44
(d) 14
(e) $98.56
(a) How much profit does Lucy earn when she sells a necklace?
Since the problem states that her profit is the sale price minus the cost of materials and labor, we have the following equation.
P = $15.99 - $3.38 - $5.57
P = $12.61 - $5.57
P = $7.04
So her profit is $7.04 per necklace.
(b) Write a fraction of the profit per sale price of the necklace. Record your answer as a fraction using whole numbers.
The raw fraction is 7.04/15.99, to get rid of the decimal point, multiply top and bottom by 100, getting 704/1599.
The prime factors of 704 are 2,2,2,2,2,2,11 and the prime factors of 1599 are 3,13,41. Since neither 704, nor 1599 share any common factors, the fraction can't be reduced and the final answer is 704/1599.
(c) What decimal of every dollar of the sale price of the necklace is profit using the fraction from Part (b)?
Pardon the lack of formatting
704/1599 = 0.4403
Rounded to the nearest hundredth gives 0.44
(d) Lucy collected $223.86 selling necklaces at a craft fair. How many necklaces did Lucy sell? Show your work.
This question is asking for total cost. So divide the $223.86 by the sale price of $15.99.
$223.86 / $15.99 = 14
14 necklaces were sold.
(e) How much profit did she earn from the number of necklaces she sold? Show your work.
Since we know from (a) that she has $7.04 profit per necklace, just multiply the amount of profit by the number sold. So
$7.04 * 14 = $98.56</span>
<span>Just substitute M=4.2 in the given equation. Make the whole log term the subject.
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<span>Then, remove the log,:
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