Mensuration Questions

Multiple choice
  1. 5544 cm2

  2. 5045 cm2

  3. 4244 cm2

  4. 4345 cm2

  5. None of these

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

Volume of sphere = (4/3)πr³ = 38808 cm³. Using π = 22/7, we get r³ = 38807 × 3/(4π) = 9261, so r = 21 cm. Curved surface area = 4πr² = 4 × (22/7) × 21² = 5544 cm². The formula relating volume and surface area of a sphere is CSA = 4πr² where r is derived from volume.

Multiple choice
  1. Quantity I > Quantity II

  2. Quantity I ≥ Quantity II

  3. Quantity II > Quantity I

  4. Quantity II ≥ Quantity I

  5. Quantity I = Quantity II or relation can't be established

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

Given h + d = 22m, and d = 2r, so h + 2r = 22. Quantity I: h/r = 30/7, so h = 30r/7. Substituting: 30r/7 + 2r = 22 gives 44r/7 = 22, so r = 3.5m and h = 15m. Volume I = π * 3.5² * 15 = 183.75π ≈ 577.3 m³. Quantity II: h = 14m, so d = 22 - 14 = 8m, r = 4m. Volume II = π * 4² * 14 = 224π ≈ 703.7 m³. Since 703.7 > 577.3, Quantity II > Quantity I.

Multiple choice
  1. Only I and III

  2. Only I

  3. Only III

  4. Any of the two

  5. None of these

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

To find CSA of a cone (πrl), we need radius and slant height. Statement I gives height (35m). Statement II gives diameter is 20% more than height, so diameter = 42m, radius = 21m. From I and II: l = √(35² + 21²) = √(1225 + 441) = √1665 ≈ 40.8m. From I and III: Base area πr² = 5544 gives r = 21m, then same slant height calculation. From II and III: From III, πr² = 5544 gives r = 21m; from II, diameter is 1.2×height, so height = 42/1.2 = 35m. Then l = √(35² + 21²). Any two statements together provide sufficient information.

Multiple choice
  1. 95 m

  2. 115 m

  3. 118 m

  4. 105 m

  5. None of these

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

Circular ground with rectangular tank. Rectangle area = 130 × 110 = 14300 m². Remaining area = 20350 m². Total circle area = 14300 + 20350 = 34650 m². Circle area = πr² = 34650, so r² = 34650/π ≈ 34650/3.14 ≈ 11035. r = √11035 ≈ 105 m. The radius is 105 meters.

Multiple choice
  1. $98900 mm2$
  2. $78200 mm2$
  3. $9720 cm2$
  4. $97200 mm2$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Length is 200% more than width, so L = w + 2w = 3w. Perimeter P = 2(L+w) = 2(3w+w) = 8w = 1440, so w = 180 mm. Length L = 540 mm. Area = L × w = 540 × 180 = 97200 mm². Option C is wrong because it uses cm² not mm².

Multiple choice
  1. $828 cm3$
  2. $672 cm3$
  3. $500 cm3$
  4. $1000 cm3$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When squares of side 2 cm are cut from corners, the new dimensions of the box base become (25-4) = 21 cm and (20-4) = 16 cm. The height of the box is 2 cm (the side of the cut square). Volume = length × width × height = 21 × 16 × 2 = 672 cm³.

Multiple choice
  1. 7: 6

  2. 7: 3

  3. 6: 7

  4. 3: 7

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

For a cylinder with curved surface area (CSA) = 2πrh = 264 and volume = πr²h = 924, dividing volume by CSA gives r/2 = 924/264 = 3.5, so r = 7. Substituting r = 7 in CSA: 2π(7)h = 264, we get h = 6. The ratio of semi-diameter (r) to height is 7:6. Option A correctly states this ratio.

Multiple choice
  1. Rs. 12178

  2. Rs. 11178

  3. Rs. 10178

  4. Rs. 14728

  5. Rs. 13178

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

The length and breadth are 23x and 12x respectively. Perimeter = 2(23x + 12x) = 70x = 210, so x = 3. Area = 69 × 36 = 2484 sq ft. Cost = 2484 × 4.50 = Rs. 11178.

Multiple choice
  1. $130$
  2. $65$
  3. $78$
  4. $104$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Area of rhombus = (d1 × d2)/2 where d1, d2 are diagonals. Given area = 3000 and d1 = 50, we get d2 = (2×3000)/50 = 120. Each diagonal divides the rhombus into 4 right triangles with legs (d1/2) = 25 and (d2/2) = 60. The side is the hypotenuse: sqrt(25² + 60²) = sqrt(625 + 3600) = sqrt(4225) = 65 units.

Multiple choice
  1. $2 : 1$
  2. $3 : 1$
  3. $2 : 3$
  4. $3 : 2$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Let outer radius R=24 cm and inner radius r. Given inner area = 1/3 of area between circles: πr² = (1/3)π(R² - r²). Simplifying: 3r² = R² - r², so 4r² = R², giving r = R/2. Circumference ratio = 2πR/2πr = R/r = 2:1. Option A is correct.

Multiple choice
  1. 12 cm and 5 cm

  2. 24 cm and 10 cm

  3. 60 cm and 25 cm

  4. 30 cm and 12.5 cm

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

Let radii be 12k and 5k (diameter ratio 12:5). Sum of areas: π(12k)² + π(5k)² = π(144k² + 25k²) = 169πk². Target circle area: π(32.5)² = 1056.25π. Equating: 169k² = 1056.25, so k² = 6.25 and k = 2.5. Therefore radii are 12×2.5 = 30 cm and 5×2.5 = 12.5 cm. Note that options A and B show diameters, not radii.