Answer:
60T = 12x - 1
Step-by-step explanation:
In speed distance and time, time(t) is given by
time = distance(d)/speed(s)
total distance ran = x miles
case 1
d = 1 mile
speed = 4 miles per hour
as time = distance(d)/speed(s)
t = 1/4
____________________________
case 2
speed = 5 miles per hour
it is given that out of x miles for first mile and last mile her speed was 5 miles per hour
thus distance for this speed can be calculated by
subtracting first and last mile from x miles
therefore
distance = x-2 miles\
t = (x-2)/5
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case 3
distance = 1 mile
speed = 6 miles per hour
t = 1/6
______________________________
Total time T as required will be sum of time for the 3 case calculated above
T = 1/4 + (x-2)/5 + 1/6
T = 1/4 + (x - 2)/5 + 1/6 (taking LCM of 6,5,4 as 60 and solving)
T = (15 + 12x - 24 + 10)/60
T = (12x - 1)/60
60T = 12x - 1
Thus, equation 60T = 12x - 1 represents her time T