ElectricPavlov

volume of a sphere    4/3 pi r^3

4/3 pi r^3 = 4571 mm³

r = 10.295     mm    (new radius)                        1/2 r = 5.15      volume = 4/3 pi r^3 = 571.38 mm³  

I think there is none....zero....nada  >>>>>>>>>>

  an odd number  x  an even number is always even number result.

cos c = 4/5         

cos c = sin b

find sin b      cos^2 + sin^2 = 1

                       9/25 + sin^2 =1

                                  sin^2 = 16/25

                                     sin b = 4/5                   cos c = sin b = 4/5

Given    b = 1/5 j

b+4 = 1/3 ( j -4)      sub in the red equation

1/5j  + 4  = 1/3 ( j-4)

1/5 j  + 4 = 1/3 j - 4/3

3/15 j + 4 = 5/15 j - 4/3

-2/15 j  = -4 - 4/3

j = 40    initially                       she gives away 4   to have 36 left

Not sure how you got that answer !   

    arctan (8/31) = ?

Is there more information given?

8 w  +  8 h  = 144 (4)

w = 4h

(8) 4 h + 8 h = 144(4)

h = 14.4

square perimeter = 16h = 230.4 units         ) Just as Logarhythm found !)

 1 jar  - 2/3 - 1/6 - 1/12   =  1 - 8/12 - 2/12 - 1/12   = 1/12 are 'other'

1/12  * 23310 = other colored marbles = ..............  

Ina RIGHT triangle , recall that    Tan = opposit side / adjacent side

tan ?    =   8/31

arctan ( 8/31) = ?    

Future value of ordinary annuity ( payments at end of period)

FV = pmt * [  ((1+i)ⁿ -1 )/ i ]     

                                                 i = decimal interest per period = .0425       pmt = $ 600      n = periods = 10 

Plug in those numbers and see what you calculate for FV.....