The surface area of hemisphere is given by:

Where r is radius of hemisphere.
We are given diameter = 250 ft.
We know that radius = half of diameter.
Radius of dome = 1/2 (250) = 125 ft.
Now let us plug the value of radius in the formula,

Surface Area of dome = 98125 square foot.
Approximately 76
You take (250 - 81 =169)=19 so you keep doing that until you run out of members
Answer:
19.6
Step-by-step explanation:
The ratio of brown paint to white paint is, 5:7 or
so if he bought 14 gallons of white paint we need to figure out:

which we can as it only has one unknown:
5x=14×7
5x=98
x=19.6
So the answer is 19.6