Question
A train of length (L + 50) meters crosses a man running in
the same direction in 25 seconds. The same train crosses a bridge of length (L - 100) meters in 30 seconds. If the speed of the man is 18 kmph, then find the value of 'L'.Solution
Let the speed of the train be 'S' m/s,
Speed of the man = 18 kmph = 5 m/s
Length of the train = (L + 50) metres
ATQ,
L + 50 = (S - 5) X 25
L = 25S - 175 --- (i)
Sum of the length of Train and bridge = L + 50 + L – 100 = (2L - 50) metres
Now,
2L - 50 = 30S
Using value of 'L' from equation (i), we get:
2 X (25S - 175) - 50 = 30S
Or, 50S - 350 - 50 = 30S
Or, 20S = 400
So, 'S' = 20
Required value of 'L' = 25 X 20 - 175 = 325
Find the circumference and area of a circle of radius 7 cm. Take π = 22/7.
The base of the triangular area is two times its height. If the cost of farming area is Rs. 2000 and Rs. 80 per hectare. Find its base (1 hectare = ...
The breadth of a rectangle is increased by 9 cm, it will become twice the length of the rectangle. If the new perimeter is 294 cm, then find the origina...
Two wires A and B are made of the same material and have the same length but different cross-sectional areas. If the resistance of wire A is 9 times the...
The cost of fencing a rectangular field at the rate of Rs. 5/metre is Rs. 350. If the length of the field is 11 metres more than its breadth, then find ...
In a rectangular floor of length and breadth of 19 metres and 6 metres, respectively, square tiles each of 2 metre edge length are to be laid. If the co...
The perimeter of an equilateral triangle is 36√3 cm. Find its height.
The volume of a cuboid is 480 cubic cm. If its length is 10 cm and breadth is 8 cm, find its height.
Find the length of a wire radius 0.40 cm which can completely cover the surface of a cylinder whose height is 1.6m and base radius 21 cm?
A wire, when bent in the form of a square encloses an area of 121 sq. cm. If the same wire is bent in the form of a circle, what is the area enclosed by...
Relevant for Exams:
