Mensuration Questions

Multiple choice
  1. 85.5

  2. 92.5

  3. 90.5

  4. 87.5

  5. Insufficient data

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

Surface area S = 4 * pi * r^2. If S_B = 4 * S_A, then r_B^2 = 4 * r_A^2, so r_B = 2 * r_A. Volume V = (4/3) * pi * r^3. V_B = (4/3) * pi * (2 * r_A)^3 = 8 * V_A. The volume of A is 7/8 of V_B, which is 87.5% lower.

Multiple choice
  1. 1232 cm3

  2. 1848 cm3

  3. 1632 cm3

  4. 1078 cm3

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

Curved Surface Area (CSA) = 2*pi*r*h. Total Surface Area (TSA) = 2*pi*r*h + 2*pi*r^2. Ratio CSA/TSA = 1/2 implies 2*pi*r*h = 2*pi*r^2, so h = r. TSA = 2*pi*r^2 + 2*pi*r^2 = 4*pi*r^2 = 616. r^2 = 616 / (4 * 22/7) = 49. r = 7, h = 7. Volume = pi*r^2*h = (22/7) * 49 * 7 = 1078.

Multiple choice
  1. 180 cm

  2. 182 cm

  3. 184 cm

  4. 186 cm

  5. 191 cm

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

Area of circle = pi * r^2 = 22/7 * 14 * 14 = 616. Area of rectangle = 1166 - 616 = 550. Length = 25, so width = 550 / 25 = 22. Circumference = 2 * 22/7 * 14 = 88. Perimeter = 2 * (25 + 22) = 94. Sum = 88 + 94 = 182.

Multiple choice
  1. 6 : 13

  2. 10 : 13

  3. 12 : 5

  4. 13 : 5

  5. 15 : 13

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

Curved surface area is pi*r*l and total surface area is pi*r(l+r). The ratio pi*r*l / pi*r(l+r) = l / (l+r) = 13/18. This implies 18l = 13l + 13r, so 5l = 13r, or l/r = 13/5. Using l^2 = h^2 + r^2, we find h^2 = l^2 - r^2 = (13r)^2/25 - r^2 = 144r^2/25, so h/r = 12/5.