Mensuration Questions

Multiple choice
  1. 324.7 cm3

  2. 311.5 cm3

  3. 281.4 cm3

  4. 269.5 cm3

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

Lateral surface area (LSA) = 2*pi*r*h = 154. Total surface area (TSA) = 2*pi*r*h + 2*pi*r^2. Given LSA/TSA = 2/3, we have 154 / (154 + 2*pi*r^2) = 2/3. Solving this gives 2*pi*r^2 = 77. Using LSA=154, we find r=3.5 and h=7. Volume = pi*r^2*h = 269.5.

Multiple choice
  1. 156.4 sq.in

  2. 188.4 sq.in

  3. 264.3 sq.in

  4. 423.9 sq.in

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

Volume = 1/3 * pi * r^2 * h = 301.44. With r=3k and h=4k, 1/3 * 3.14 * 9k^2 * 4k = 301.44 => 37.68k^3 = 301.44 => k^3 = 8 => k=2. So r=6, h=8. Slant height l = sqrt(6^2 + 8^2) = 10. Lateral surface area = pi * r * l = 3.14 * 6 * 10 = 188.4.

Multiple choice
  1. 352 sq. cm

  2. 380 sq. cm

  3. 448 sq. cm

  4. 496 sq. cm

  5. 540 sq. cm

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

Volume 1 = 2.5*4*8 = 80. Volume 2 = 4*9*12 = 432. Total volume = 512. New solid: 16*4*h = 512 => 64h = 512 => h = 8. Surface area = 2(lw + lh + wh) = 2(16*4 + 16*8 + 4*8) = 2(64 + 128 + 32) = 2(224) = 448.

Multiple choice
  1. 1102 cu. cm

  2. 1078 cu. cm

  3. 981 cu. cm

  4. 841 cu. cm

  5. 655 cu. cm

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

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