CPhill

1/8.........each spin is independent of the results that occured before........we have a 1/8 chance of landing in any sector with every spin.....

I assume that the man is 900 ft from the house and the helicopter is directly over this house....so.....the height, h, of the helicopter can be found thusly:

tan (49)  = h / 900

h = 900*tan (49)  = about 1035.33 ft

a + b = 3

a - b =  -1      add these equations

2a = 2       divide both sides by 2

a = 1

So....if ab  = 2, then.....

(1)b = 2    so b  = 2

And    a/b =   1/2

Here's a graph of all the equations and their solution at the intersection point (1,2)......I have substituted  x, y for a, b

https://www.desmos.com/calculator/0bye1246yo

5a*95=? a=37

5(37) *95 =  17575

500 * 1.15 =   $575

A 30% discount means that the selling price is 70% of the original...so...  the sales price is .......

40 * .70    =  $28

It appears that the program will output a number that is 1/5 of the input....so .....6  →  6/5

tan x = 3/5    .......we can find x using the tangent inverse  [arctangent]

arctan (3/5)  = about  30.96°

Here is some good info on this [ I hope it's not too "technical" ] 

http://www.math.ubc.ca/~bwallace/maths100_180_taylor_notes.pdf

Indeed........we are not limited to expansions only around 0, as some of the examples show.......!!!

The length that Jacob bought is given by :

(7/8)  * (4/5)   =  

28 / 40  =

7/10    yards