Problema Solution
As Emily is riding her bike on a road, she spots Emerson skating in the same direction 1/2 mile in front of her. After she passes him, she can see him in her rear mirror until he's 1/2 mile behind her. Emily rides at a constant rate of 12 miles per hour, and Emerson skates at a constant rate of 8 miles per hour. For how many minutes can Emily see Emerson?
Answer provided by our tutors
let
t = the time that Emily sees Emerson in hours
in t hours Emily will pass distance of 12t miles
in t hours Emerson will pass distance of 8t miles
since Emily is 1/2 mile behind and 1/2 mile after him her distance is by 1/2 + 1/2 = 1 mile bigger than the distance that Emerson will pass thus:
12t = 8t + 1
by solving we find:
t = 1/4 hr
t = (1/4)*60 min
t = 15 min
click here to see the step by step solution of the equation:
Emily will see Emerson for 15 minutes.