Average speed

Question

Cameron is 70 miles from Ahmed. They are traveling towards each other. If Ahmed travels 4 mph faster than Cameron and they meet after 5 hours. How fast was each traveling

Answer 1

Cameron:

speed = x

distance = y

time = 5

 

s= d/t

x= y/5

 

Ahmad

speed = x+4
distance = 70-y
time = 5

x+4 = (70 -y) / 5

x = ((70 -y) /5  ) -4

 

equating both x

 

y/5 = ((70 -y) /5 ) -4

 

(y/5 ) + 4 = (70-y) / 5

 

(y+20) /5 = (70-y)/5

 

y + 20 =70- y

 

2y = 50

 y = 25

 

Cameron speed

 x =y/5 = 25/5 = 5 m/h

 

Ahmed speed

x+4 =5+4 =9 m/h

Answer 2

v = Cameron's speed

u = Ahmed's speed = v + 4

t = 5 hrs

d = total distance traveled between the two = vt + ut = 70 miles

 

vt + ut = d

 

(v + u)t = d

 

[v + (v + 4)]t = d

 

(2v + 4)t = d

 

v = (d/t - 4)/2 = (70/5 - 4)/2 mph = 5 mph

 

v + 4 = (5 + 4) mph = 9 mph

 

Cameron:  5 mph

Ahmed:  9 mph

 

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