ElectricPavlov

The first car travels :       rate * time = distance 

                               40 mi/hr * ( 6.5 hr)  = 260 miles 

the second car also travels this distance, but does it in   3.5 hours   ( 5 to 8:30) 

                           260 miles / 3.5 hr = 74.29 mi/hr     ( 74 2/7 mi/hr) 

Joey has a head start of  3 hrs 50 min = 3.8333 hrs   and travels   3.8333 hr * 60 m/hr =  230 miles before Mike left 

              now there are only 300 - 230 = 70 miles left to cover 

They approach each other at   60 + 80 = 140 m/hr   and will cover this distance in    70 mi/ 140 m/hr = 30 minutes after Mike leaves 

      then they would meet at  11:20 + 30 min =  11:50 AM     <=====NOT in the afternoon !

AVERAGE speed = total distance / total time 

total time = 4 = 5 = 9 hrs 

then remember    rate * time = distance 

                              60 mi/hr * 4 hr = 240 mi 

                              80 mi/hr * 5 hr = 400 mi       total distance = 640 mi 

AVERAGE speed = 640 mi / 9 hr = 71 . 11  mph     ( 71  1/9 mph) 

220  x 30 % = 66 pounds of fat initially       and has 120 pounds of nonfat nonmuscle     220 - 66 -120 = 34 pounds of muscle etc

200 x 20 % =  40 pounds of fat                   plus 120 pounds of nonfat nonmuscle           200 - 40 - 120 = 40 pounds of muscle etc

40 - 34 = 6 pounds of muscle gained

Let the numbers be     n-1     n      n+1    and   n+2

   The numbers are ALMOST 

 n^4 = 461^2 - 1 = 212520      <======take 4th root of both sides

n ~~  21 

                   so try  20 21 22 23    =  212520     Bingo !   On first try .......

Remember :   Distance / rate = time 

Car 1 travels for   75 km /  60 km /hr  = 1.25 hours

Car 2 travels for   75 km/75 km/hr      = 1 hour 

   1.25 hr - 1 hr = .25 hr     which is 15 minutes 

Original volume = 6 x 6 x 6 = 216 in^3 

Now remove three triangular pyramids with side length 2 inches 

   slant height 2 inches translates to height   sqrt 5    and area of 1/2  * 2 * sqrt 5 = sqrt 5  in^2 

      for a volume  1/ 3 (base ) (height) = 1/3 ( sqrt 5)(sqrt 5 ) =  5/3  in^3 

          eight of these then subtract 40 / 3 in^3  from the original volume=  for a final volume 202 2/3 in^3 

Your question does not ask for the inverse of any of the functions....sooooo....

f(x) = 3x-4      then  for f (g(x) )  put   g(x) in place of 'x'

   f(g(x)) = 3 (5x+c) - 4    = 15x + 3c - 4 

and 

g(f(x)) = 5 (3x-4) +c  = 15x - 20 + c         

Now your question is missing something.....I will assume you want the two to be equal for all x 

   15x -20 + c = 15x + 3c - 4 

  -20 + c = 3c -4 

    -16 = 2c 

         c = - 8           

30 m is the hypotenuse of a right triangle

sin = opposite leg / hypotenuse 

sin 25 = height / 30 

30 sin 25 = 12. 67 m    but you have to add the one meter hand height for a total  = ~ 14 m 

This is a DOME shaped parabola......there will be no MIMIMUM value ...or   - ∞