Since they move toward each other, their relative speed is 110 km/h + 100 km/h = 210 km/h.


It is the rate decreasing the distance between them.


So, the time before they meet each other is time =  =  hours.


Moving at the rate 100 km/h, George will cover   = 333.333 km.


Jim will cover   = 366.667 km.

Let t be time when they meet each other (in hours).

During this time, Peter will cover the distance 100*t kilometers.
Jim will cover 110*t kilometers.

At the moment they meet each other, they cover the entire distance of 700 kilometers:

100*t + 110*t = 700.

Or, which is the same,

(100 + 110)*t = 700,

which gives you   t =  =  hours.   (*)


Notice that (*) is the same formula for t as you get in the first solution.


Now complete the solution is the same way as it was done above.