Question
If the lateral surface area (3
faces) of a regular tetrahedron is 75√3 cm2, find its volume.Solution
ATQ, LSA = 3*(√3/4)*a2 = (3√3/4)*a2 (3√3/4)*a2 = 75√3 (3/4)*a2 = 75 a2 = 100 a = 10 cm Volume: V = a3/(6√2) V = 103/(6√2) = 1000/(6√2) = 500/(3√2) = (250√2)/3 cm3 FINAL ANSWER: (250√2)/3 cm3
The volume of a cube is 64 cm³. If the cost of painting the cube is Rs. 15 per cm², then find the cost of painting five faces of the cube.
The circumference of a circle is 44 cm and the length of the rectangle is 4 times the radius of the circle. Find the area (in cm2) of the rec...
The average weight of five friends A, B, C, D and E is (x+8) years while the average weight of C and E is (x-8) kg. If the weight of another person F is...
A figure is formed by revolving a rectangular sheet of dimensions 7cm ×4cm about its length. What is the volume of the figure. thus formed. (in c...
A barrel has 140 liters of mixture of alcohol and water, in which water is 10%. 30 litre of this mixture was taken out and replaced with “X”...
A square is converted into a rectangle by increasing its length by 30 % and decreasing its width by 10%. Which of the following statements is true?
- 'A hall has a floor covered with rectangular tiles, each measuring 90 cm by 50 cm. The hall’s dimensions are 720 cm in length and 3 meters in width. Find...
The ratio between the length and the breadth of a rectangular park is 3 : 2. If a man cycling along the boundary of the park at the speed of 12 km/hour...
Due to economic surge the price of eggs suddenly reduced by 40%. This enabled a woman to buy 64 more for $30. Then the reduced price per dozen is :
Find the surface area of the smallest cube that can perfectly fit a sphere of volume 47916π cm3 inside it.
Relevant for Exams:
