Question
Two buildings are collinear with the base of a tower and
are at a distance 9m and 16m from the base of the tower. The angles of elevation from these two building of the top of the tower are complementary. What is the height of the tower?Solution
Let the height of the tower be h And ∠CBD = θ and ∠ DAC = 90 – θ In ∆ BCD tan θ = CD/BC = h/9 …………(i) In ∆ ACD tan(90 - θ) = CD/AC cot θ = h/16 ……………………….(ii) On multiplying Equation (i) and (ii) tan θ × cot θ = h/9 × h/16 1 = h²/144 Now h = 12 m
A spherical metallic shell with 6 cm external radius weighs 6688 g. What is the thickness of the shell if the density of metal is 10.5 g per cm3
Which of the following types of virus, also known as spacefiller virus,infects a file using empty sections?
A merchant has two types of sugar. Type A costs 50 per kg, and Type B costs 70 per kg. In what ratio should the two types be mixed to get a mixture that...
What will be the compound interest on a sum of Rs 22,000 after 3 years at the rate of 6 percent per annum?Â
A certain sum of money becomes Rs. 1900 in 1 year and 2600 in 3 years at certain rate of simple interest. Find the sum of money invested.
A and B together can complete a task in 12 days. A alone can complete the task in 20 days. In how many days can B alone complete the task?
In a triangle ABC, the internal bisector of ∠A meets side BC at D. If AB = 6 cm, AC = 9 cm, and BC = 12 cm, what is the length of BD?Â
A boat can travel 225 km downstream in 5 hours. If the speed of the boat in still water is 7 times the speed of the stream, how m...
The current age ratio of Q to P is 5:3. If Q is 8 years older than P, determine the ratio of their ages after 8 years.
Relevant for Exams:
