two planes departed simultaneously from parallel runways at
two planes departed simultaneously from parallel runways at an airport. they flew in the same direction. after 5 hours, the faster plane was 300 km ahead of the slower plane. find the distance flown by each plane if the total of these distances is 5 300 km.
Solution
Let x and y be the speeds ofthe planes.
 In 5 hours,
 The distance flown by the faster plane = 5x
 The distance flown by the slower plane = 5y
 Given, the distance between the planes
 5x-5y = 300 ...(1)
 Also, total distance flown by the planes
 5x+5y = 5300 ...(2)
 (1)+(2)=> 10x = 5600
 x = 5600/10
 x = 560 kmph
 Substituting in (1), 5*560-5y = 300
 -5y = 300-2800
 -5y = -2500
 y = (-2500)/(-5)
 y = 500 kmph
 The distance flown by the faster plane = 5*560 = 2800km
 The distance flown by the slower plane = 5*500 = 2500km

