ElectricPavlov

Probability of a 6    1 out of 6 chance   1/6

Probabilty of a 5                                    1/6

1/6 + 1/6 = 2/6 = 1/3

Calculate the area of the LARGE triangle...then subtrat the two smaller triangles.

You can calculate the angles of ADE.....find the hypotenuse....you are given two sides

    then you can calculate the angles FEB  CDG   etc

       Example : 180 - AED - 90  = FEB       to find the side lengths of those triangles and their areas......etc,,,

Or calculate the area AED and add the rectangle when you find the side lengths.....

I come up with the following:

the 75 degree angle between the two first chords is repeated until the endpoint is back to A

the ARC this angle encompasses is  2 * 75 = 150 degrees

Keep adding 150 degree shifts until the endpoint coincides with A:

The LCM of 150 and 360 degrees (which will bring us back to A) is 1800

    1800/150 = 12  angles which will require a total of 13 chords to complete

Simple interest   20,000 x .06 x 4 = $ 4800     total after 4 yrs   20000 + 4800 = 24800

Componded interest:

   quarterly interest   7% / 4 = .0175  for 16 quarters

20 000 (1+.0175)^16 = 26 398.59

26398.59 - 24800 = ~~  $ 1599    more interest with 7% plan

Oxford to Dayton   7.89 km

Oxford to Ashland 5.26 km

7.89 - 5.26 = 2.63 km farther

9+ (-3)

Yah....that is the maximum revenue , but the question only asked for the price which would generate that maximum.... 

Yah, TR.... I thought that too,,,but it seemed more likely that it was e^(.2x)   to me as e is usually used in exponential functions that way.....but who knows????         Unless guest responds, we are BOTH correct !  

Revenue will be given by the price x number of books sold

p (130-5p)

-5p^2 + 130p = revenue       (this is a dome shaped parabola)

Max will be p =    -b/2a   =   - (130)/((2* -5)  = 13  dollars    (just as CU found !)

Since you are looking for a DIFFERENCE 9 has to be subtraced from 8....and since you want it in the form of an addition problem, 8 + (-9) would fit the bill,   A          (though poorly worded problems are somewhat ambiguous.....some may say that D would also work)