Problema Solution

dave and his sister ann jog to school daily. dave jogs at 9 mile per hour, and ann jogs at 5 miles per hour. when dave reaches school, ann is 1/2 mile from the school. how far do dave and ann live from their school?

Answer provided by our tutors

let


v1 = 9 mph the speed of Dave


v2 = 5 mph the speed of Ann


d = the distance to school (the distance they jog)


t = the time that Dave need to reach school


since speed = distance/time follows speed*time = distance


when Dave reaches school, Ann is 1/2 mile from the school


v1*t = d


v2*t = d - 1/2


if we plug the values for v1 and v2 we get the system:


9t = d


5t = d - 1/2


by solving the above system of equations we find:


d = 1.125 mi


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Dave and Ann live 1.125 miles away from their school.