Mensuration Questions

Multiple choice
  1. 120

  2. 27.72

  3. 92.28

  4. 105.86

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

Sides 24, 26, 10 form a right triangle (10² + 24² = 26²). Area = 1/2 × 10 × 24 = 120 cm². Three circles of radius 4.2 cm at vertices with angles 90°, ~67.38°, ~22.62° cover total sector area = (90+67.38+22.62)/360 × π × 4.2² = 180/360 × (22/7) × 17.64 = 27.72 cm². Triangle excluding circles = 120 - 27.72 = 92.28 cm².

Multiple choice
  1. 144

  2. 169

  3. 196

  4. 171

  5. None of these

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

Circumference=2πr=88, so r=14 cm. Curved surface area of cylinder=2πrh=2π×14×2=56π=175.84 cm² (using π=22/7: 56×22/7=176 cm²). None of the options (144, 169, 196, 171) match 176 or 175.84. Option E is correct.

Multiple choice
  1. 20 Kachwansi = 1 Biswansi

  2. 20 Biswansi = 10 Biswa

  3. 20 biswa = 1 bigha

  4. 1 bigha = 55 x 55 square yards

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

The traditional land measurement system in Uttar Pradesh follows: 20 Kachwansi = 1 Biswansi, 20 Biswansi = 1 Biswa, and 20 Biswa = 1 Bigha. Therefore, option B claiming '20 Biswansi = 10 Biswa' is incorrect - it should be 20 Biswansi = 1 Biswa. 1 Bigha is approximately 55 x 55 square yards in UP. This question asks which measurement is NOT correct, so B is the right answer because it has the wrong conversion.

Multiple choice
  1. 2626

  2. 3384

  3. 2994

  4. 3316

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

For a cone with height h=35 cm, CSA = πrl. Given: πrl = 4×πr² (base area). So l = 4r. Using l² = r² + h²: (4r)² = r² + 35². 16r² = r² + 1225. 15r² = 1225. r² = 81.67, r ≈ 9.04 cm. Volume = (1/3)πr²h = (1/3)×π×81.67×35 ≈ 2994 cm³ (approx).

Multiple choice
  1. 0.8

  2. 2

  3. 1.6

  4. 2.5

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

Curved surface area = 2πrh = 17.5, Volume = πr²h = 14. Dividing volume by CSA: (πr²h)/(2πrh) = r/2 = 14/17.5 = 0.8, so r = 1.6. This elegant solution uses the relationship between the two formulas rather than solving for h separately. The radius of 1.6 m is Option C.

Multiple choice
  1. 2772 cm3

  2. 2744 cm3

  3. 2432 cm3

  4. 2140 cm3

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

Given r + h = 25, so h = 25 - r. Total surface area = 2πr(r + h) = 1100. Substituting: 2πr(25) = 1100, so r = 1100/(50π) = 22/π. Using π = 22/7: r = 22/(22/7) = 14, so h = 25 - 14 = 11. Volume = πr^2h = (22/7) × 14^2 × 11 = (22/7) × 196 × 11 = 22 × 28 × 11 = 2772 cm^3.

Multiple choice
  1. $2 : 3$
  2. $4 : 3$
  3. $3 : 7$
  4. $6 : 7$
  5. $7 : 6$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Sphere volume = (4/3)πr³ = cylinder volume = πr²h. Height h = 4r/3. Sphere surface area = 4πr². Cylinder surface area = 2πr² + 2πrh = 2πr² + 2πr(4r/3) = 2πr² + 8πr²/3 = 14πr²/3. Ratio = 4πr² : 14πr²/3 = 4 : 14/3 = 12 : 14 = 6 : 7. Option D is correct.

Multiple choice
  1. 21

  2. 10.5

  3. 42

  4. 11

  5. 15

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

For a cylinder, CSA : TSA = 2πrh : 2πr(r + h) = 3 : 5. This means 2πrh / [2πr(r + h)] = 3/5, which simplifies to h / (r + h) = 3/5. Cross-multiplying: 5h = 3r + 3h, so 2h = 3r, giving h = 1.5r or r = (2/3)h. Also, CSA = 2πrh = 1848, so 2πr(1.5r) = 1848. With r = 14, we get h = 1.5 × 14 = 21 cm.

Multiple choice
  1. 8 cm 8 सेमी

  2. 10 cm 10 सेमी

  3. 7 cm 7 सेमी

  4. 14 cm 14 सेमी

  5. None of these इनमें से कोई नहीं

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

Circle area = π(7)² = 154 cm² (taking π = 22/7). Let width = w, then length = w + 3. Rectangle area = w(w + 3). Given: 154 - w(w + 3) = 84, so w(w + 3) = 70. This gives w² + 3w - 70 = 0, or (w + 10)(w - 7) = 0. Since width can't be negative, w = 7 cm. Length = 7 + 3 = 10 cm.

Multiple choice
  1. 205

  2. 704

  3. 924

  4. 1078

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

Sphere volume = (4/3) × (22/7) × 7³ = (4/3) × (22/7) × 343 = 1,432 2/3 cm³. Cone volume = (1/3) × (22/7) × 7² × 10 = (1/3) × 22 × 7 × 10 = 1,540 1/3 cm³. Wait: let me recalculate. Cone = (1/3) × (22/7) × 49 × 10 = 1,540 cm³ (exactly since 49 cancels with 7). Sphere = (4/3) × 22 × 49 = (4/3) × 1,078 = 1,437 1/3. Difference = 1,540 - 1,437 1/3 = 102 2/3. This doesn't match options. Let me recalculate: (4/3) × (22/7) × 343 = 4,312/3 = 1,437.33. Cone = (1/3) × (22/7) × 49 × 10 = 10,780/21 = 513.33? No, (22/7) × 49 = 154, then × 10 = 1,540, then ÷ 3 = 513.33. So sphere - cone = 1,437.33 - 513.33 = 924.

Multiple choice
  1. 9034

  2. 10841.6

  3. 13552

  4. 8131.2

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

For a cylinder, total surface area (TSA) = 2πr(r + h) and curved surface area (CSA) = 2πrh. Given TSA:CSA = 18:11, we have 2πr(r + h):2πrh = (r + h):h = 18:11, so r:h = 7:11. With h = 22 cm, r = 14 cm. Volume = πr²h = π(14)²(22) = π(196)(22) = 4312π ≈ 13552 cm³.