Question
A train with 12 compartments of equal length takes 30
seconds to cross a pole and 40 seconds to cross a 240-metre-long platform. If 6 compartments of the train are removed, then how long would it take to cross a pole?Solution
Let the original length of the train = ‘d’ metres
Then, distance covered by the train in 30 seconds = ‘d’ metres
Distance covered by the train in 40 seconds = (d + 240) metres
So, distance covered in (40 – 30) = 10 seconds = (d + 240 – d) = 240 metres
So, speed of the train = 240 ÷ 10 = 24 m/s
So, original length of the train = 24 × 30 = 720 metres
After removing 6 compartments, length of the train = 720 × (6/12) = 360 metres
So, required time taken = 360 ÷ 24 = 15 seconds
The sides of a triangle are 15 cm, 20 cm, and 25 cm. A smaller triangle is drawn inside it such that its sides are proportional to the original triangle...
What is the area of a triangle whose sides are 13 cm, 14 cm and 15 cm?
What is the height of an equilateral triangle if each of its sides is 4√3 cm?
A triangle has sides 13 cm, 14 cm, and 15 cm. What is the radius of its incircle?
- Determine the perpendicular drawn from a vertex to the opposite side in an equilateral triangle with side length 8√3 cm.
An equilateral triangle ABC is surmounted on a square BCDE whose area is 500 cm². Find the altitude of triangle ABC.
Find the area of a trapezium whose parallel sides are 12 cm and 18 cm and the distance between them is 9 cm.
Find the length of BC, if ΔABC ~ ΔRQP and AC = 18 cm, RP = 12 cm and QP = 8 cm.
- Find the altitude of an equilateral triangle whose side is 8√3 cm.
In a right-angled triangle, the perimeter is 60 cm. If the base is 12 cm and the height is 16 cm, find the length of the hypotenuse.
Relevant for Exams:
