## Time Speed and Distance

Two cars P and Q start from two points A and B towards each other simultaneously. They meet for the first time 40 km from B. After meeting they exchange their speeds as well as directions and proceed to their respective starting points. On reaching their starting points, they turn back with the same speeds and meet at a point 20 km from A. Find the distance
between A and B.

A. 110 km
B. 120 km
C. 130km
D. 100 km.

See our previous ‘Questions of the Day’:
Quant Question Of The Day: 273
Quant Question Of The Day: 272

1. In such questions if first meeting happens at A km from one end and second meeting at B km from another end then distance between two ends is equal to 3A-B.

In this question 3×40-20=100

Provided that the speed ratio (faster is to slower) should be less than or equal to 2.

1. Take distance = d
Now time would be equal for covering d-40 and 40 with speeds Va and Vb so (d-40)/Va=40/Vb
Va/Vb=d-40/40

In the same wat for second meeting Va/Vb=(d+d-20)/d+20

Equate the above 2 equations solve the quadratic.

In the same way if we take 40=a and 20=b … you will get d=3a-b

But the interesting thing is the ratio of sppeds of faster is to slower should be less than or equal to 2 otherwise second meeting may take place as overtaking not by way of face to face … coming from oppostite directions.

### Recent Forum Posts/Questions/Answers

• In a test match in cricket, the scores of Rohit and Vir...

By nhuadovan , 5 months ago

• The 111th digit of the series 149162536496481........ i...

By nhuadovan , 5 months ago

• how many perfect squares of natural numbers between 300...

By nhuadovan , 5 months ago

• Find the number of ways to distribute 2n different ball...

By nhuadovan , 5 months ago

• A cube is divided into two parts by a plane passing thr...

By nhuadovan , 5 months ago

• @utkarsh-garg25 how

By traciblack , 5 months ago

• Thank you for sharing the list ... i will try to read o...

By Peter Virdee , 12 months ago

• The collection of the questions are really great it wil...

By Peter Virdee , 1 year ago

• Mark bought 45 grinders for Rs. 2215, while carrying h...

By Alexander Zingman , 1 year ago

• Great thread ,i tried to do these but not able to do..t...

By Alexander Zingman , 1 year ago

• I will try 1000 SC to practice

By Peter Virdee , 1 year ago