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1 - Physics style solution
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.
Solved.
2 - Algebra style solution
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.
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To wide your horizon, look into the lessons
- Travel and Distance problems
- Travel and Distance problems for two bodies moving in opposite directions
- Travel and Distance problems for two bodies moving in the same direction (catching up)
in this site.
They contain basic introductory Travel and Distance problems solved by different methods.
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