Two motor-cyclists John and Kevin were $800 \text{km}$ apart and travelling towards each other at a constant speed. They started at the same time, meeting after $8$ hours. If Kevin started $1\dfrac{1}{2}$ hours later than John, they would be $70 \text{km}$ apart $8$ hours after John started. At what speed was John travelling in $\text{km/h}$? 
Overseas Competition->Knowledge Point->Word Problem Modules->Equation Word Problems->Word Problems for Linear Equations with One Variable
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