Mensuration Questions

Multiple choice
  1. $523.9 \ \displaystyle cm^{3}$
  2. $520.91 \ \displaystyle cm^{3}$
  3. $512.91 \ \displaystyle cm^{3}$
  4. $510.91 \ \displaystyle cm^{3}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The volume of a hemisphere is (2/3) * pi * r^3. Using r = 6.3 and pi = 22/7: (2/3) * (22/7) * (6.3)^3 = (2/3) * (22/7) * 250.047 = 523.9056. Rounding to one decimal place gives 523.9.

Multiple choice
  1. $125.6\:m$
  2. $1256\:m$
  3. $12.56\:m$
  4. $1.256\:m$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Length of cylinder = 1.2m = 120cm. Diameter = 10cm. Circumference = pi * 10 = 31.4cm. Number of turns = 120cm / 0.3cm = 400 turns. Total length = 400 * 31.4cm = 12560cm = 125.6m.

Multiple choice
  1. $\displaystyle 2\pi r^{2}$
  2. $\displaystyle 3\pi r^{2}$
  3. $\displaystyle 4\pi r^{2}$
  4. $\displaystyle 8\pi r^{2}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The curved surface area of a sphere is 4 * pi * r^2. A hemisphere is half of a sphere, so its curved surface area is 2 * pi * r^2.

Multiple choice
  1. $\displaystyle 603cm^{3}$
  2. $\displaystyle 720cm^{3}$
  3. $\displaystyle 548cm^{3}$
  4. $\displaystyle 637cm^{3}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Volume of cylinder = pi * r^2 * h = pi * 6^2 * 8 = 288 * pi. Volume of cone = 1/3 * pi * r^2 * h = 1/3 * pi * 6^2 * 8 = 96 * pi. Remaining volume = 288 * pi - 96 * pi = 192 * pi. Using pi approx 3.14159, 192 * 3.14159 = 603.18, which rounds to 603.

Multiple choice
  1. $\displaystyle \frac{352}{21}m^{3}$
  2. $\displaystyle 576m^{3}$
  3. $\displaystyle \frac{376}{9}m^{3}$
  4. $\displaystyle 600m^{3}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The volume of a hemisphere is (2/3)πr^3. For r = 2 cm, this is (2/3)π(8) = 16π/3 cm^3, approximately 352/21 cm^3 using π = 22/7. The numerical answer matches option A, but its displayed unit should be cm^3, not m^3.