ElectricPavlov

Let x = 0. 515515515......                        (    515/999   from the web2.0 calculator)

1000x = 515.515515......

-x               -.515515515.....

  999x = 515.0  

then x = 515/999

this is close:

y = 1.0896 (1.5^x) + 1003.725  

1/5   + 1/25  + 1/125

25/125  +  5/125  + 1/125

31/125

31 ÷ 125

= .248

x = origianl amount

spending 3/8 ths leaves  5/8 x        spending 4/7 of this leaves   3/7  (5/8 x)   and this = 45

3/7 ( 5/8 x) = 45    solve for x

x = 168

They all bought the same number of fruits

Let 'x' be the number     d = price of orange    a = price of apple

5d + ( x-5)a = 7.80        <====== Multiply by -2.2 and add to the second equation ( this is to cancel ou the 'd')

11d + (x-11)a = 9.00

-2.2(x-5)a + (x-11)a = -2.2(7.80)(9.00)

simplifying this results in xa = 6.80         this is the amount Chris spent on 'x' apples

x = total numer of items

Luke has   3/8 x - 5      <==== this is given

   the remainder will be    x -  ( 3/8 x -5)     and this equals Miko's 25

x - (3/8 x - 5 ) = 25

5/8x + 5 = 25

x = 32 total items

The 4 square sides are all equal     32/4 = 8 inches = side length

   this is also the circle DIAMETER  so the circle radius = 4 inches

area of circle = pi r^2 =   pi 4^2 = 16 pi   in ²

a = b + 42      given     re written as    a-42 = b

then

(a-118) * 3 = (b+118)     sub in the red equation for b

3a - 354 = ( a-42    + 118 )

a = 215 originally ...... then he gives away 118   to have 97 in the end.

10 people would half the time to 6 hours.....     20 people would half the 6 hours to 3 hours.

You're welcome!   Hope you understood how to solve it.....    ~EP