A metallic sphere of radius 10.5 cm is melted and then recast into small cones…
2022
A metallic sphere of radius 10.5 cm is melted and then recast into small cones each of radius 3.5 cm and height 3 cm. Then the number of cones thus formed is:
- A.
112
- B.
126
- C.
132
- D.
138
Attempted by 1 students.
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Correct answer: B
Step 1: Identify given dimensions.
Radius of sphere (R) = 10.5 cm Radius of cone (r) = 3.5 cm Height of cone (h) = 3 cm
Step 2: Write volume formulas.
Volume of sphere = (4/3) * π * R^3 Volume of cone = (1/3) * π * r^2 * h
Step 3: Equate volumes to find number of cones (n).
n * (1/3) * π * r^2 * h = (4/3) * π * R^3 n = (4 * R^3) / (r^2 * h)
Step 4: Substitute values and calculate.
n = (4 * 10.5^3) / (3.5^2 * 3) n = (4 * 1157.625) / (12.25 * 3) n = 4630.5 / 36.75 n = 126
The number of cones formed is 126.