## Time and Distance

**Speed = Distance/Time****Distance = Speed × Time****Time = Distance/Speed**

**To convert Kilometers per Hour(km/hr) to Meters per Second(m/s)**

**To convert Meters per Second(m/s) to Kilometers per Hour(km/hr)**

**1. If some distance is travelled at x km/hr and the same distance is travelled at y km/hr then the average speed during the whole journey is given by:**

**Average Speed=**

**2. If a person travels a certain distance at x km/hr and returns at y km/hr, if the time taken to the whole journey is T hours then the one way distance is given by**

**One Way Distance**

**3. If two persons A and B start their journey at the same time from two points P and Q towards each other and after crossing each other they take a and b hours in reaching Q and P respectively, then**

**4. If the ratio of the speeds of A and B is a : b, thenthe ratio of the times taken by them to cover the same distance is**

**5. If the same distance is covered at two different speeds S1 and S2 and the time taken to cover the distance are T1 and T2, then the distance is given by**

## Questions Asked from this Chapter:

### Question Type 1: Based on basic concept of Time & Distance

**Example:**

A man crosses a road 250 metre wide in 75 seconds. His Speed in Km/hr is:

a) 10

b) 12

c) 12.5

d) 15

**Solution:**

### Question Type 2: Based on Train and Platform/Bridge

**Example:**

A train 200 metre long running at 36 Kmph takes 55 seconds to cross a bridge. The length of the bridge is:

a) 375 m

b) 300 m

c) 350 m

d) 325 m

**Solution:**

### Question Type 3: Based on Train and a man/Pole/Signal

**Example:**

A train 100 m long is running at the speed of 30 Km/hr. The time(in seconds) in which it will pass a man standing near the railway line is:

a) 10

b) 11

c) 12

d) 15

**Solution:**

### Question Type 4: Based on Two trains crossing each other in opposite direction

**Example:**

Two trains 105 metres and 90 metres long, run at the speed of 45 Km/hr and 72 Km/hr respectively, in opposite directions on parallel tracks. The time which they take to cross each other, is:

a) 8 seconds

b) 6 seconds

c) 7 seconds

d) 5 seconds

**Solution:**

### Question Type 5: Based on Two trains travelling in same direction at different speed

**Example:**

Two trains of equal length are running on parallel lines in the same direction at 46 Km/h and 36 Km/h. The faster train passes the slower train in 36 seconds. The length of each train is:

a) 82 m

b) 50 m

c) 80 m

d) 72 m

**Solution:**

### Question Type 6: Based on a train/man/car changes his speed, then he reaches his destination before latter

**Example:**

The student go to school at the rate of 2.5 Km/h and reaches 6 minutes late. If he travels at the speed of 3 Km/h, he is 10 minute early. The distance between the school and his house is:

a) 5

b) 4

c) 3

d) 1

**Solution:**

### Question Type 7: Based on any Train crossing both platform and man/pole at same time

**Example:**

A train passes a platform 110 m long in 40 seconds and a boy standing on the platform in 30 seconds. The length of the train is:

a) 100 m

b) 110 m

c) 220 m

d) 330 m

**Solution:**

### Question Type 8: Based on a car travelling with x/y speed of its usual speed

**Example:**

Walking at 6/7th of his usual speed a man is 25 minutes late. His usual time to cover this distance is:

a) 2 hours 30 minutes

b) 2 hours 15 minutes

c) 2 hours 25 minutes

d) 2 hours 10 minutes

**Solution:**

### Question Type 9: Based on Average Speed

**Example:**

A train moves with a speed of 30 Kmph for 12 minutes and for next 8 minutes at a speed of 45 Kmph. Find the average speed of the train?

a) 37.5 Kmph

b) 36 Kmph

c) 48 Kmph

d) 30 Kmph

**Solution:**

### Question Type 10: Based on Ratio

**Example:**

The speed of two train are in the ratio 6:7. If the second train runs 364 Km in 4 hours, then speed of the first train is:

a) 60 Km/h

b) 72 Km/h

c) 78 Km/h

d) 84 Km/h

**Solution:**

### Question Type 11: Based on Races

**Example:**

In a race of 200 metres, B can give a start of of 10 metres to A, and C can give a start of 20 metres to B. The start that C can give to A, in the same race is:

a) 30 m

b) 25 m

c) 29 m

d) 27 m

**Solution:**