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Brad has a cylindrical barrel with radius 10 inches and height 15 inches. He wants to fill it from a well, using a bucket in the shape of a hemisphere with a radius of 10 inches. How many trips must Brad make to the well in order to fill the barrel?

 Nov 10, 2019
 #1
avatar+308 
+3

First, we want to find the volume of the barrel. The formula for the volume of a cylinder is h* π * r^2. Substituting 15 in for h and 10 in for r, we get that the volume of the barrel is 1500π. Now, we must find the area fo the bucket. The formula for the volume of a hermisphere is (2/3)* π  * r^3. Substituting 10 in for r, we get that the volume of the bucket is 2000/3π. We divide 1500π by 2000/3π to get 9/4, but Brad can't make 1/4 of a trip to the well and get water, so the answer is 3 trips.

 Nov 10, 2019
 #2
avatar+2551 
+1

Very nice solution!

CalculatorUser  Nov 10, 2019
 #3
avatar+308 
+2

Thank you!

ThatOnePerson  Nov 10, 2019
 #4
avatar+11059 
0

Brad has a cylindrical barrel with radius 10 inches and height 15 inches. He wants to fill it from a well, using a bucket in the shape of a hemisphere with a radius of 10 inches. How many trips must Brad make to the well in order to fill the barrel?

 

laugh

 Nov 10, 2019

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