Mensuration Questions

Multiple choice
  1. 7 cm.

  2. 12 cm.

  3. 49 cm.

  4. 14 cm.

  5. None of these इनमें से कोई नहीं

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

Perimeter of rectangle = 2(18 + 26) = 88 cm. Circle circumference = 88 cm, so 2πr = 88, thus r = 14.01 cm. Diameter = 2r = 28.01 cm. None of the options (7, 12, 49, 14 cm) match. Option E is correct.

Multiple choice
  1. 79 cm.2

  2. 86 cm.2

  3. 102cm.2

  4. 66 cm.2

  5. None of these इनमें से कोई नहीं

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

Let triangle height = h. Then r = 1.4h. Area equality: (1/2) × 44 × h = π(1.4h)². This gives 22h = π × 1.96h², so h = 22/(1.96π) ≈ 3.57cm. Area = π(1.4 × 3.57)² ≈ 79 cm².

Multiple choice
  1. 1276 m2 1276 मी.2

  2. 1486 m2 1486 मी.2

  3. 1386 m2 1386 मी.2

  4. 1156 m2 1156 मी.2

  5. None of these इनमें से कोई नहीं

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

Square perimeter = 84 m, so side = 84/4 = 21 m. This is the circle's radius. Circle area = πr² = (22/7) × 21² = (22/7) × 441 = 22 × 63 = 1386 m². Option C (1386) matches this calculation exactly when using π = 22/7.

Multiple choice
  1. 272 cm. 272 सेमी

  2. 380 cm. 380 सेमी

  3. 280 cm. 280 सेमी

  4. Can not be determined तय नहीं कर सकते

  5. None of these इनमें से कोई नहीं

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

Circle: diameter = 42 cm, radius = 21 cm. Area = π(21)² = 1386 cm² (using π = 22/7). Circumference = 2π(21) = 132 cm. Total area = 2611 cm², so square area = 2611 - 1386 = 1225 cm². Square side = √1225 = 35 cm. Perimeter = 4 × 35 = 140 cm. Sum = 132 + 140 = 272 cm, making option A correct.

Multiple choice
  1. 8 m. 8 मी.

  2. 12m. 12मी.

  3. 13m. 13मी.

  4. 17m. 17मी.

  5. 20m. 20मी.

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

Cylinder circumference = 66 = 2πr, so r = 33/π. Rectangle area = 42 × 66 = 2772. This equals cylinder volume = πr²h = π(33/π)²h = 1089h/π. So 2772 = 1089h/π, giving h = 2772π/1089 = 8π. Therefore height = 8 m.

Multiple choice
  1. 5450 sq. cm. 5450 वर्ग सेमी.

  2. 5220 sq. cm. 5220 वर्ग सेमी.

  3. 5080 sq. cm. 5080 वर्ग सेमी.

  4. Can't be determined निर्धारित नहीं किया जा सकता है

  5. None of these इनमें से कोई नहीं

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

Circle diameter = 70 cm, radius = 35 cm. Circumference = 2πr = 70π ≈ 220 cm. Square perimeter = 380 - 220 = 160 cm, so side = 160/4 = 40 cm. Area of circle = πr² = π(35)² = 1225π ≈ 3850 sq. cm. Area of square = 40² = 1600 sq. cm. Total area ≈ 3850 + 1600 = 5450 sq. cm.

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

Let length = 23x, breadth = 12x. Perimeter = 2(23x + 12x) = 70x = 210, so x = 3. Area = 23x × 12x = 276x² = 276 × 9 = 2484 sq ft. Cost = 2484 × 4.50 = 11178.

Multiple choice
  1. 6256

  2. 6250

  3. 6156

  4. 6150

  5. 6242

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

Area of square plot = 529 sq ft. Side length = √529 = 23 ft. Perimeter = 4 × 23 = 92 ft. Cost of fencing = 92 × 68 = Rs. 6256. The calculation is straightforward: find the side from the area, calculate perimeter, multiply by cost per foot.

Multiple choice
  1. 14 cm

  2. 28 cm

  3. 7 cm

  4. 56 cm

  5. 24 cm

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

Given CSA/TSA = 4/5 and CSA = 1232. For a cylinder, CSA = 2πrh and TSA = 2πr(r+h). Therefore, 2πrh / 2πr(r+h) = 4/5, which simplifies to h/(r+h) = 4/5. Cross-multiplying: 5h = 4r + 4h, so h = 4r. If CSA = 1232 = 2πr(4r) = 8πr², then r = 7 cm and h = 28 cm. Answer B is correct.

Multiple choice
  1. 10

  2. 7

  3. 10.5

  4. 3.5

  5. None of these इनमें से कोई नहीं

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

The square has side 2r since circles at adjacent corners touch. Square area = 4r². Four quarter-circles at corners form one full circle of area πr². Remaining area = 4r² - πr² = r²(4 - π) = 94.5. Solving: r² = 94.5/(4 - π) ≈ 110.1, so r ≈ 10.5 cm.

Multiple choice
  1. 1228

  2. 1723

  3. 1540

  4. 1617

  5. None of these इनमें से कोई नहीं

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

For a cylinder: CSA/TSA = 2πrh/(2πrh + 2πr²) = h/(h+r) = 3/5. So 5h = 3h + 3r, giving h = 1.5r. Given CSA = 2πrh = 462, substituting h = 1.5r: 2πr(1.5r) = 462. Using π = 22/7: 2 × (22/7) × 1.5 × r² = 462. Solving: r² = 49, so r = 7 cm and h = 10.5 cm. Volume = πr²h = (22/7) × 49 × 10.5 = 1617 cm³.

Multiple choice
  1. 680 sq. cm 680 वर्ग सेमी

  2. 800 sq. cm 800 वर्ग सेमी.

  3. 770 sq. cm 770 वर्ग सेमी.

  4. 720 sq. cm 720 वर्ग सेमी.

  5. None of these इनमें से कोई नहीं

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

Let cylinder height=h and radius=r. Given diameter=h/4, so h=8r. Total length=h+2r=10r=35, thus r=3.5cm. Surface area = cylinder CSA + 2 hemisphere surfaces = 2πrh + 4πr² = 16πr² + 4πr² = 20πr². With r=3.5, area=245π ≈ 770 sq.cm.

Multiple choice
  1. 2 cm

  2. 3 cm

  3. 4 cm

  4. 5 cm

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

Let radii be r and R. For external tangency: r + R = 14 cm. Sum of areas: πr² + πR² = 130π, so r² + R² = 130. Squaring the first equation: (r+R)² = r² + 2rR + R² = 196. Substituting: 130 + 2rR = 196, so rR = 33. Solving the quadratic x² - 14x + 33 = 0 gives (x-3)(x-11) = 0, so radii are 3 cm and 11 cm. The smaller radius is 3 cm.

Multiple choice
  1. $\(πr(l + r)\)$
  2. $\(2πr(l + r)\)$
  3. $\(πrl\)$
  4. $\(πrl^2\)$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The total surface area of a cone includes the base (circle with area πr²) and the curved surface (πrl). Combined: πr² + πrl = πr(l + r). Option B incorrectly doubles this value. Option C is only the curved surface area without the base. Option D has an incorrect squared slant height.

Multiple choice
  1. 2 : 3

  2. 2 : 1

  3. 4 : 3

  4. 8 : 3

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

Volume = 13824 = 24³, so original cube side = 24. Original surface area = 6 × 24² = 3456. When cut into 8 equal cubes, each small cube has side = 24/2 = 12. Each small cube surface area = 6 × 12² = 864. Three small cubes total = 3 × 864 = 2592. Ratio = 3456 : 2592 = 4 : 3.