



 
Hi Gayle, First you need to know how many cubic inches there are in an imperial gallon. Google can help with this. Type 1 Imperial gallon in cubic inches into the Google search engine and the response is 1 Imperial gallon = 277.419547 cubic inches. Suppose the radius of the cylinder is $r$ inches. Write an expression for the volume of a cylinder of radius $r$ inches and a height of 42 inches. Set that equal to $45 \times 277.419547$ and solve for $r.$ Write back if you need more assistance,  


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