Question

David and john started driving towards each other at 11 am and met each other at 2 30 pm on the same day david and john started from different cities which are 420 miles apart if david avarge speed is 10 miles per hour lower than johns what is the speed of at whice john was driving in miles hours.

Answer 1

Let the speed of John be x and that of David be (x - 10).

The time taken for them to meet is :

1430 hrs (in 24 hrs format) - 1100hrs (24 hrs) = 3hrs 30 minuyes

In 3.5 hrs Each will have covered :

John = 3.5 x

David = 3.5x - 35

Note : distance = speed × time

At the point where they meet they will have covered the total distance between them

Hence :

3.5x + 3.5x - 35 = 420

7x = 455

x = 65

John's speed is thus :

65miles per hour