Question 1092174
height of cylinder: 89 inches
Radius (1/2 diameter): 30 inches
The flat top has no bearing on the volume of the cylinder.
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1) Maximum amount of feed - Volume: 
V = πr2h 
V = π30^2 x 89 
= 2827.433 x 89 
= 251641.57 cu. in. or 145.63 cubic feet
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2) How much more to fill the cylinder to capacity
V = πr2h 
V = π30^2 x 32
= = 2827.433 x 32 = 90477.86 cu. inches = 1.483 m^3
Cylinder capacity . . . : 251641.57 cu. in.
Less current content . .: 90477.86 cu. in.
Amount needed to fill . : 161163.71 cu. in. = 2.641 m^3
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3) How much should she buy
Bag of feed: 0.15 m^3
needed: 2.641 m^3
To buy: 2.641/0.15 = 17.6 (she has 2 choices, buy 17 bags and leave a little space at the top of the cylinder or buy 18 bags and have some feed left over)