Wiley Edge Time, Speed and Distance Quiz-2

To find the time taken to cross each other, we need to calculate the relative speed of the two trains. The relative speed is the sum of their individual speeds.
The speed of Train A is 54 km/h, which is equal to (54 * 1000) / 3600 = 15 m/s.
The speed of Train B is 72 km/h, which is equal to (72 * 1000) / 3600 = 20 m/s.
Therefore, the relative speed of the two trains is 15 m/s + 20 m/s = 35 m/s.
The total distance to be covered is the sum of the lengths of the two trains, which is 120 meters + 90 meters = 210 meters.
To find the time taken, we can use the formula: time = distance / speed.
Substituting the values, we get time = 210 meters / 35 m/s = 6 seconds.
Hence, it will take 6 seconds for the two trains to completely cross each other.

To find the length of the platform, we need to determine the relative speed between the two trains.
The sum of their speeds is 60 km/h + 50 km/h = 110 km/h = 110,000 m/3600 s = 30.56 m/s.
As the trains take 10 seconds to cross each other, the effective length of the two trains is (30.56 m/s × 10 s) = 305.6 meters.
Since one train is half the length of the other, the length of the larger train is 2 × 305.6 meters = 611.2 meters.
Now, subtracting the length of the larger train from the total distance covered in passing the platform (30.56 m/s × 30 s) gives us the length of the platform:
(30.56 m/s × 30 s) - 611.2 m = 305.6 meters.
Therefore, the length of the railway platform is 305.6 m

Since the individual catches up to his predecessor in 3 hours and is traveling at a speed of 15 kmph, he covers a distance of 45 km (15 kmph x 3 hours) during this time.

Since his predecessor started 2 hours earlier, the total time the predecessor has been cycling is 2 hours + 3 hours = 5 hours.

To find the speed of the predecessor, we divide the total distance covered by the predecessor (45 km) by the total time (5 hours), which gives us 9 kmph.

Since Swimmer X can outswim Swimmer Y by 150 meters in an 800-meter race;
so X beats Y by 18.75meters for every 100 meter swim and Swimmer Y beats Swimmer Z by 30 meters in a 300-meter race;
so Y beats Z by 10 meters for every 100 meter it implies that Swimmer X is faster than Swimmer Z by a combined margin of 18.75 + 10 = 28.75 meters.
Therefore, in a 500-meter race, Swimmer X will beat Swimmer Z by 143.75 meters

let the length of the car be X, we can equate the speed equations;
Distance covered to completely cross tunnel 1 = 500+ X
Distance covered to completely cross tunnel 2 = 300+ X;
(500+X)/80=(300+X)/50
X= 33.33 meters

Let's assume the distance between the starting place and the destination is 'd' kilometers.
When traveling downstream, the effective speed of the boat is the sum of the boat's speed in still water and the stream's current, i.e., 8 km/h + 3 km/h = 11 km/h.
So, the time taken to travel downstream is d/11 hours.
When traveling upstream, the effective speed of the boat is the difference between the boat's speed in still water and the stream's current, i.e., 8 km/h - 3 km/h = 5 km/h.
So, the time taken to travel upstream is d/5 hours.
According to the given information, the total time taken for the round trip is 3 hours.
Therefore, we can set up the equation d/11 + d/5 = 3.
Solving this equation, we find d = 10.3125 km.

To find the time it takes for the boats to meet, we can consider their relative speed.

The speed of Boat A relative to Boat B is the sum of their individual speeds, which is 8 km/h + 10 km/h = 18 km/h.

The distance between the two boats is 72 km.

Therefore, the time it takes for them to meet is 72 km divided by 18 km/h, which equals 4 hours.

The rate at which the second candle is approaching the first candle = 5-3= 2 cm/hr . The difference to be covered to get same length= 15-12= 3 cm . So the time after which the candles will be of the same length = 3/2 hours= 1hr 30min.

Here, the distance covered by the first train to overtake the second train is 150 meters, and the time taken is 25 seconds. Relative Speed = 150 meters / 25 seconds = 6 meters per second
Relative Speed = 6 meters per second * 3.6 = 21.6 km/h
Speed of the second train = Speed of the first train - Relative Speed;Speed of the second train = 80 km/h - 21.6 km/h = 58.4 km/h

Since the boat's speed is 4:3 compared to the current, the time it takes to go along with the current is inversely proportional to the speed ratio.So , let the speed of the boat be 4x and speed of current be 3x . So, (speed downstream/speed upstream)=(4x+3x)/(4x-3x) = Time upstream/time downstream . Time upstream = 7*2.5hr =17.5 hrs.