The volume of a cone is 88 pi cubic feet. Its height is 6 feet. Singha is finding the diameter of the base of the cone. Her work is shown below. V = one-third pi r squared h. Step 1: 88 pi = one-third pi r squared (8). Step 2: 88 pi = 2 pi r squared. Step 3: 88 pi minus 2 pi = r squared. Step 4: 86 pi = r squared. Step 5: 16.44 = r. Step 6: 32.88 = diameter. What is Singha's error?

Question

Mathematics

Gabrielle

16 July, 19:56

The volume of a cone is 88 pi cubic feet. Its height is 6 feet. Singha is finding the diameter of the base of the cone. Her work is shown below. V = one-third pi r squared h. Step 1: 88 pi = one-third pi r squared (8). Step 2: 88 pi = 2 pi r squared. Step 3: 88 pi minus 2 pi = r squared. Step 4: 86 pi = r squared. Step 5: 16.44 = r. Step 6: 32.88 = diameter. What is Singha's error?

+3

Answers (2)

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Luz Berry · Answer 1

Singha has made a mistake in step 3

The actual diameter is 13.2 ft.

Step-by-step explanation:

Volume of cone = 88π cubic ft.

height (h) = 6ft

We know that,

Volume = (1/3) (π x r²x h)

88π = (1/3) (π x r² x 6)

88π (3) = π x r² x 6

88π (3) / 6 = π x r²

44π = π x r²

44π/π = r²

r² = 44

r = 6.6ft

diameter = 2 (6.6) = 13.2ft

Harper · Answer 2

he made a mistake in step 3