Suppose that this person drives at r mph going to the mountains, and gets there in 12 hours. Returning, this person drives at (r+20) mph and gets home in 8 hours. We don't know the distance yet, but can solve for the initial speed, r, by setting
d = 12r = (r+20)(8). Solving for r, r=40 mph (going) and (40+20)mph = 60 mph (returning. Since d=12 r, d = (12 hrs)(40 mph) = 480 miles (answer).
b) The surface area is 564.5. Picture below.
4. Three possibilities.
Formula for volume of a cylinder: πr^2h
Formula for volume of sphere: 4/3πr^3
If the radius of the sphere is 1 inch than the volume is: 4.18879 or 4.19 rounded.
I used substitution on this website https://www.omnicalculator.com/math/volume
Just plug in the 4.18879 at the cylinder volume and put in a random number in the radius or height whichever you want then it'll give you the one you left blank. You'll find three possibilities for the radius and height of 4.18879 volume.
Answer:
5: c=65 d=125 e=60
6: c= 58 d= 121 e=63
7. a=55 b=64 c=61
8. a=61 b=55 c=64
Step-by-step explanation: :)