<PRE><B>Question 1198781</B>
Krystal left the hospital and drove toward the lake at an average speed of 45 km/h. -
Heather left four hours later and drove in the opposite direction with an average speed of 80 km/h. Find the number of hours Heather needs to drive before they are 430 km apart.
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In 4 hours, K moved 4*45 = 180 kms
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Moving in opposite directions, speeds are added.
45 + 80 = 125 km/hr
--- 
430 - 180 = 250 kms to go
--- 250/125 = 2 hours
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