Mensuration Questions

Multiple choice
  1. 6cm

  2. 18cm

  3. 12cm

  4. 25cm

  5. 34cm

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

Volume of cylinder = pi * r^2 * h. Volume of cone = (1/3) * pi * r^2 * h. Difference = (2/3) * pi * r^2 * h = 4928. Given h/r = 6/7, let h=6k, r=7k. (2/3) * (22/7) * (49k^2) * (6k) = 4928. 44 * 7 * 2 * k^3 = 4928. 616 * k^3 = 4928. k^3 = 8, so k = 2. Height = 6 * 2 = 12.

Multiple choice
  1. 134%

  2. 150%

  3. 240%

  4. 643%

  5. 86%

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

The original surface area is 2*pi*r^2 + 2*pi*r*h = 2*pi*9 + 2*pi*3*5 = 18*pi + 30*pi = 48*pi. Cutting the cylinder into 5 pieces creates 4 new cuts, each adding 2 circular faces of area pi*r^2 = 9*pi. Total added area is 8 * 9*pi = 72*pi. Percentage increase = (72*pi / 48*pi) * 100 = 1.5 * 100 = 150%.

Multiple choice
  1. 336

  2. 672

  3. 728

  4. 1344

  5. 934

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

The radius of the inscribed circle in a trapezium is related to the height. If the radius is 12, the height h = 24. For a tangential trapezium, the sum of opposite sides is equal. Sum of parallel sides = Sum of oblique sides = 26 + 30 = 56. Area = 0.5 * (sum of parallel sides) * height = 0.5 * 56 * 24 = 672.

Multiple choice
  1. 49 sq cm

  2. 64 sq cm

  3. 25 sq cm

  4. 196 sq cm

  5. 81 sq cm

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

First, find the radius of the circle using the area formula, pi * r^2 = 2464, which gives r = 28 cm. Since the perimeter of the square is equal to this radius, we have 4 * side = 28, meaning the side of the square is 7 cm. Finally, the area of the square is side^2, which equals 49 sq cm.

Multiple choice
  1. 5 : 2

  2. 1 : 1

  3. 2 : 1

  4. 4 : 1

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. Given CSA = 1/3 TSA, then 3*CSA = TSA, so 6*pi*r*h = 2*pi*r*h + 2*pi*r^2. This simplifies to 4*pi*r*h = 2*pi*r^2, so 2h = r. Diameter d = 2r = 4h. Thus, d/h = 4/1.

Multiple choice
  1. 36 cm2

  2. 196 cm2

  3. 100 cm2

  4. 64 cm2

  5. 144 cm2

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

The curved surface area of a cone is pi*r*l = 1914. With r=21, l = 1914 / (22/7 * 21) = 29. Using the Pythagorean theorem, the height h = sqrt(l^2 - r^2) = sqrt(29^2 - 21^2) = sqrt(841 - 441) = 20. Since the height is half the perimeter of the square, the perimeter is 40, meaning each side is 10. The area of the square is 10^2 = 100.