ElectricPavlov

Ya got the first one.....but not the second one......  wanna try again?

The September price was 'x'     the October price was   1.2 * x

1.2 * x = 1.50

x = 1.50/1.2 = $1.25   (sept price)

September earnings     1.25 * 40% x 900 = $450.

October earnings          1.50 * 40% x 700 = $420        They earned $30 MORE in Sept

We need the point(s) where   y = 5x+6    equals  y = 9x-32    

     or    5x+6 = 9x-32       solve for x     add 32 to each side of the equation

            5x+38 = 9x           subtract 5x from both sides

                  38 = 4 x

                    9.5 = x           Now substitute theis 'x' into one of the equations to find 'y'

          y= 5(9.5) +6        y= 53.5      so   x,y  =  9.5 , 53.5   

  (you can sub 'x' in to the other equation to see if you get the same result as a check)

0.5x+1.5= -4(x-3)

                = -4x +12       add 4x to both sides

4.5x +1.5 =12                 Subtract 1.5 from both sides

4.5x = 10.5                      Divide by 4.5

x = 2 1/3

then sub  this 'x' in to one of the other equations to find 'y'

y=-4(x-3)=-4x+12

 = -4 (2 1/3) + 12 = 2 2/3       x,y = 2 1/3 , 2 2/3           

Total alcohol in the martini by mass

142 g x .30 = 43 g

15% of this goes into the bloodstream

42 g x 15% = 43g x .15= 6 gm    (if they drink the whole martini)

Welcome back, Hayley-Meister....things are a LITTLE different here...but mostly the same.....

Agree with Cphil...missed the 6 mw part

p(n) = POWER = 6 (.98)^n  milliwatts      where n = number of reflections....

   Sorry!

One reflection mirror results in new beam of   (1) (.98)    (since .02 is lost)

    next reflectoin of THIS beam (1)(.98)  results in    (1) (.98)(.98)

         Next time    it reflects    (1) (.98)(.98)(.98)

              etc

so  b^n    would be beam stength:  (1) (.98)^n = (.98)^n      Where n is the number of mirrors ....

84  x  1.12  = 94.08

820 x (1- .25) = 615

0.33333...... > 0

Agree with Hectictar !     Diameter is given in this question ....radius was in the last question !        Good catch Hec !