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11 grade maths others

A wooden toy was made by scooping out a hemisphere of same radius from each end of a solid cylinder. If the height of the cylinder is 10 cm, and its base is of radius 3.5 cm, find the volume of wood in the toy. [Use π = 22/7]

A. 425
B. 290
C. 474.83
D. 205.33

Profile image of Aniket Singh
1 Year agoGrade
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1 Answer

Profile image of Askiitians Tutor Team
1 Year ago

To solve this problem, we need to calculate the volume of the wooden toy, which is obtained by subtracting the volume of the two hemispheres (scooped out) from the volume of the original cylinder.

Step 1: Volume of the cylinder The formula for the volume of a cylinder is: Volume of cylinder = π × r² × h
Here,
r = 3.5 cm (radius of the base)
h = 10 cm (height of the cylinder)

Substitute the values: Volume of cylinder = (22/7) × (3.5)² × 10
= (22/7) × 12.25 × 10
= (22 × 122.5) / 7
= 385 cm³

Step 2: Volume of a hemisphere The formula for the volume of a hemisphere is: Volume of a hemisphere = (2/3) × π × r³
Here, r = 3.5 cm

Substitute the values: Volume of one hemisphere = (2/3) × (22/7) × (3.5)³
= (2/3) × (22/7) × 42.875
= (2 × 22 × 42.875) / (3 × 7)
= (1885.5) / 21
= 89.78 cm³

Step 3: Total volume of the two hemispheres Since the toy has two hemispheres scooped out: Total volume of hemispheres = 2 × 89.78 = 179.56 cm³

Step 4: Volume of the wooden toy The volume of the wooden toy is the volume of the cylinder minus the total volume of the two hemispheres: Volume of wooden toy = Volume of cylinder - Volume of hemispheres
= 385 - 179.56
= 205.44 cm³

Final Answer: The volume of wood in the toy is approximately 205.33 cm³.

The correct option is D. 205.33.