Mensuration Questions

Multiple choice
  1. $\dfrac{100}{7}\ cm$
  2. $18\ cm$
  3. $15\ cm$
  4. $\dfrac{200}{11}\ cm$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Volume of cylinder = pi * 6^2 * h = 36 * pi * h. Volume of 10 cones = 10 * (1/3 * pi * 3^2 * 12 + 2/3 * pi * 3^3) = 10 * (36 * pi + 18 * pi) = 10 * 54 * pi = 540 * pi. 36 * pi * h = 540 * pi, so h = 540/36 = 15 cm.

Multiple choice
  1. $10$ cm
  2. $\displaystyle 10\sqrt{2}$ cm
  3. $\displaystyle \frac{5\sqrt{2}}{2}$ cm
  4. $\displaystyle \frac{10\sqrt{3}}{3}$ cm
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Volume of sphere = 4/3 * pi * 5^3 = 500/3 * pi. Volume of cone = 1/3 * pi * r^2 * h. Given h = 5/2. So 500/3 * pi = 1/3 * pi * r^2 * 5/2. 500 = r^2 * 5/2. r^2 = 200. r = sqrt(200) = 10*sqrt(2).

Multiple choice
  1. 3 cm

  2. 1 cm

  3. 4 cm

  4. 2 cm

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The container volume is 540pi cubic centimetres, so each child's portion is 54pi cubic centimetres. A cone of radius r and height 4r plus a hemispherical top has volume 2pi r^3. Equating this to 54pi gives r^3 = 27, so r = 3 cm.

Multiple choice
  1. $425$
  2. $290$
  3. $474.83$
  4. $205.33$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Volume of cylinder = pi * r^2 * h = (22/7) * 3.5^2 * 10 = 22 * 0.5 * 3.5 * 10 = 385. Volume of two hemispheres = 2 * (2/3) * pi * r^3 = (4/3) * (22/7) * 3.5^3 = (4/3) * (22/7) * 42.875 = 179.66. Volume of wood = 385 - 179.66 = 205.33.

Multiple choice
  1. $A - M + C = 0$
  2. $A + M = C$
  3. $2A = M + C$
  4. $A^{2} - M^{2} + C^{2} = 0$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Let the radius be r and the height be h=2r. The volume of the cone A is (1/3)pi*r^2*(2r) = (2/3)pi*r^3. The volume of the cylinder M is pi*r^2*(2r) = 2pi*r^3. The volume of the sphere C is (4/3)pi*r^3. Substituting these, A - M + C = (2/3)pi*r^3 - 2pi*r^3 + (4/3)pi*r^3 = (6/3)pi*r^3 - 2pi*r^3 = 0.

Multiple choice
  1. $487.6$ $cm^3$
  2. $287.6$ $cm^3$
  3. $47.6$ $cm^3$
  4. None of these

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The volume of the box is 16 * 8 * 8 = 1024 cm^3. The volume of 16 spheres with radius 2 cm is 16 * (4/3 * pi * 2^3) = 16 * (32/3 * pi) = 512/3 * pi, which is approximately 536.17 cm^3. Subtracting this from the box volume gives 1024 - 536.17 = 487.83 cm^3, which is closest to 487.6 cm^3.

Multiple choice
  1. $\displaystyle 293\frac{1}{3}\, cm^{3}$
  2. $\displaystyle 293\frac{1}{5}\, cm^{3}$
  3. $\displaystyle 298\frac{1}{3}\, cm^{3}$
  4. $\displaystyle 298\frac{1}{5}\, cm^{3}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Multiple choice
  1. Volume = $681.66\, cm^{3};\,$ Total Surface Area = $ 478\, cm^{2}$
  2. Volume = $681.66\, cm^{3};\,$ Total Surface Area = $ 418\, cm^{2}$
  3. Volume = $641.66\, cm^{3};\,$ Total Surface Area = $ 478\, cm^{2}$
  4. Volume = $641.66\, cm^{3};\,$ Total Surface Area = $ 418\, cm^{2}$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The radius is 3.5 cm and the cylindrical portion has height 19 - 7 = 12 cm. Adding the cylinder volume and the volume of a sphere of radius 3.5 gives 641.66 cm^3, while the exposed area is 418 cm^2.

Multiple choice
  1. $218.02\, cm^{3}$
  2. $178.66\, cm^{3}$
  3. $158.66\, cm^{3}$
  4. $138.66\, cm^{3}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The radius is 2.1 cm. Add the volumes of the cylinder, hemisphere, and cone: pi(2.1)^2(12) + (2/3)pi(2.1)^3 + (1/3)pi(2.1)^2(7), using pi = 22/7. This gives approximately 218.02 cm^3.

Multiple choice
  1. $19.27 \%$
  2. $20.54 \%$
  3. $21.43 \%$
  4. $22.36 \%$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The box contains 2 layers * 3 rows * 4 cylinders = 24 cylinders. Each cylinder has volume V = pi * r^2 * h. The box dimensions are 4 * (2r) by 3 * (2r) by 2 * h. Box volume = 8r * 6r * 2h = 96 * r^2 * h. Total cylinder volume = 24 * pi * r^2 * h. Empty space = 96 - 24 * pi. Percentage = (96 - 24 * 3.14159) / 96 * 100 = (96 - 75.398) / 96 * 100 = 21.46%.