Question
The radius and height of a right circular cone are in
the ratio 3: 4. If its curved surface area (in cm²) is 240 π, then its volume (in cm³) is:Solution
Curved surface area of cone = π r l Volume of cone = (1/3) π r2 h Slant height = √(h2 + r2 ) Let the radius and height of the cone be 3x and 4x Slant height = √[(4x)2 + (3x)2 ] ⇒ √(16x2 + 9x2 ) ⇒ √25x ⇒ 5x Curved suface area = π × 3x × 5x2 ⇒ 240 π = π × 15x ⇒ x2 = 16 ⇒ x = 4 Radius = 12 cm Height = 16 cm Slant height = 20 cm Volume of the cone = (1/3) × π × 144 × 16 ⇒ 48 × 16 × π ⇒ 768 π
Find the wrong number in the given number series,
29, 56, 120, 245, 501, 804Â
Find the wrong number in the given number series.
3, 8, 26, 102, 398, 16392100, 2140, 2186, 2240, 2300, 2372
- Find the wrong number in the given number series.
6, 14, 30, 64, 130, 262 127, 137, 148, 164, 169, 185, 199
The series given below contains a sequence of numbers.
Accordingly identify the incorrect number.
9, 14, 24, 38, 59
45, 54, 66, 84, 99, 120, 144
Find the wrong number in given number series.
2010, 2018, 1998, 1982, 1950, 1886
5, 32, 16, 140, 105, 448
42, 50, 59, 123, 148, 360
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