Equation A (y=mx + b) is in slope intercept form.
The answer uses NMF for formatting, which you can find out about in my profile if needed:
the equation is this:
time = {total paid - 35}/{15}
Put in what we know:
time = {95 - 35}/{15}
time = {60}/{15}
time = 4 hours
The thing you have to figure out about this is the distance for each person and the time it takes for the biker to meet the runner. The rates we are told. The formula is distance = rate times time. Let's do that for the runner first. His rate is 6 so the formula so far is d = 6t. Now let's work on the time. If the biker left an hour later than the runner, then the runner has been running an hour more than the biker. Therefore, the runner's time is t + 1. Hold off on the distance part til we do for the biker what we just did for the runner. The biker's rate is 14, and we already decided that his time is t. His equation is d = 14t. Now at the exact moment the biker meets the runner their distances are the same. So if the equation for the runner is d = 6t + 6 and the equation for the biker is d = 14t and their distances are the same, by the transitive property, their rates and times are the same as well, meaning we set them equal to each other and solve for t. 6t + 6 = 14t. 6 = 8t and t = 3/4. This means that it took 45 minutes for the biker to meet the runner.
<h3>
Answer: 28</h3>
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Explanation:
Method 1
Imagine a table with 8 rows and 8 columns to represent all possible match-ups. You can actually draw out this table or just think of it as a thought experiment.
There are 8*8 = 64 entries in the table. Along the northwest diagonal, we have each team pair up with itself. This is of course silly and impossible. We cross off this entire diagonal so we drop to 64-8 = 56 entries.
Then notice that the lower left corner is a mirror copy of the upper right corner. A match-up like AB is the same as BA. So we must divide by 2 to get 56/2 = 28 different matches.
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Method 2
There are 8 selections for the first slot, and 8-1 = 7 selections for the second slot. We have 8*7 = 56 permutations and 56/2 = 28 combinations.
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Method 3
Use the nCr combination formula with n = 8 and r = 2
There are 28 combinations possible. Order doesn't matter (eg: match-up AB is the same as match-up BA).
Notice how the (8*7)/2 expression is part of the steps shown above in the nCr formula.
Pyramid Surface Area = (½ * Perimeter of Base * Slant Height) + Base Area
Pyramid Surface Area = (.5 * 56 * 11) + 14 * 14Pyramid Surface Area = 308 + 196Pyramid Surface Area =504 square millimeters
Source:http://www.1728.org/volpyrmd.htm
