Mensuration Questions

Multiple choice
  1. $5x^{2}$
  2. $6x^{2}$
  3. $\dfrac {200}{x} + x^{2}$
  4. $\dfrac {200}{x} + 2x^{2}$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Volume V = x^2 * h = 50, so h = 50/x^2. The surface area of an open-top box with a square base is the base area (x^2) plus four side faces (4 * x * h). Substituting h, we get x^2 + 4 * x * (50/x^2) = x^2 + 200/x.

Multiple choice
  1. $284cm^2$
  2. $286cm^2$
  3. $296cm^2$
  4. $300cm^2$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The volume of the metal sheet is 27 * 8 * 1 = 216 cm^3. A cube with this volume has a side length of 6 cm. The surface area of the sheet is 2 * (27*8 + 8*1 + 27*1) = 2 * (216 + 8 + 27) = 502 cm^2. The surface area of the cube is 6 * 6^2 = 216 cm^2. The difference is 502 - 216 = 286 cm^2.

Multiple choice
  1. $\dfrac { 2500 }{ 3 } \pi { cm }^{ 3 }$
  2. $5000\pi { cm }^{ 3 }\quad $
  3. $2500\pi { cm }^{ 3 }\quad $
  4. $\dfrac { 5000 }{ 3 } \pi { cm }^{ 3 }$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Cylinder radius 5, height 100 (10 balls of radius 5). Volume cylinder = pi * 5^2 * 100 = 2500pi. Volume 10 spheres = 10 * (4/3) * pi * 5^3 = 10 * (4/3) * 125 * pi = 5000pi/3. Empty space = 2500pi - 5000pi/3 = 2500pi/3.

Multiple choice
  1. $660 cm^2$
  2. $770 cm^2$
  3. $880 cm^2$
  4. $990 cm^2$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Surface area = CSA of cylinder + CSA of hemisphere + CSA of cone. CSA_cyl = 2*pi*r*h = 2*pi*5*13 = 130*pi. CSA_hemi = 2*pi*r^2 = 2*pi*25 = 50*pi. CSA_cone = pi*r*l. Slant height l = sqrt(r^2 + h^2) = sqrt(5^2 + 12^2) = 13. CSA_cone = pi*5*13 = 65*pi. Total = (130+50+65)*pi = 245*pi. 245 * 3.14 = 769.3, which rounds to 770.

Multiple choice
  1. $V=\frac {\pi r^2}{3}(h+H+2r)$
  2. $V=\frac {\pi r^2}{3}(h+2H+2r)$
  3. $V=\frac {\pi r^2}{3}(h+3H+4r)$
  4. $V=\frac {\pi r^2}{3}(h+3H+2r)$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Total volume = Volume of cylinder + Volume of cone + Volume of hemisphere. V = pi*r^2*H + (1/3)*pi*r^2*h + (2/3)*pi*r^3. Factoring out (pi*r^2)/3 gives (pi*r^2)/3 * (3H + h + 2r).

Multiple choice
  1. Rs. 12,947

  2. Rs. 13,947

  3. Rs. 14,947

  4. Rs. 15,947

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

The cone's height is 16 - 6 = 10 m. Its slant height is sqrt(10^2 + 2^2) = sqrt(104) m, so the canvas area is 2π(2)(6) + π(2)sqrt(104), approximately 139.47 m^2. At Rs. 100 per m^2, the cost is approximately Rs. 13,947.