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128 whose height is 5&prime;–0&Prime;. Allowing ¾&Prime; for locks what is the area of its pattern?

Problem 30B.—The funnel of the pump is a frustum of a cone whose lower base diameter is 8&Prime;, upper base diameter 4&Prime;, and altitude 4&Prime;. What is its area?

Problem 30C.—The spout, Fig. 171, is also a frustum of a cone whose lower base has a diameter of 3⅛&Prime;, and upper base a diameter of 2½&Prime;. The slant height may be called 7½&Prime;. What is its area?

Problem 30D.—What is the combined area of Problems 30A, 30B, and 30C?

Problem 30E.—Allowing 10 per cent for waste, what will be the cost of the material for one pump at 8 cents per square foot?