<PRE><B>Question 212139</B>
Answer: 2 hours and 50 minutes.

Robert is 500 meters ahead.

Then for the next 15 minutes Robert travels 14 km/hour (1400 meters/hour)

15 minutes is 1/4 of an hour so Robert travels 350 meters because 1400*(1/4)=350

500 + 350 = 850 so Robert is 850 meters ahead when Lionel starts.

Lionel traveling 17km/hr is 3km/hr FASTER than Robert who is going 14km/hr.

That means every hour Lionel is 300 meters closer to Robert.

Use division to see how many times 300meters/hr goes inot 850meters.

850/300 = 2 and 5/6 hours, 

so the answer is 2 hours and 50 minutes. 
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