rational expressions

Question

A bus travels 180 miles in the same time that a car travels 240 miles. if the car's speed is 15 mph faster than the speed of the bus, find the speed of the car and the speed of the bus

Answer 1

speed of bus = s

 

speed of car =s+15

 

distance traveled by bus = 180 miles

 

distance traveled by car =240

 

time taken by bus and car = t

 

So

 

s = 180/t

 

t=180/s ____________eq 1

and

 

s+15 = 240/t

 

t= 240/(s+15) ________eq 2

 

equating eq 1 and eq 2

 

180/s = 240/(s+15)

 

180(s+15) =240s

180s + 2700 = 240s

2700 = 60s

s=45

 

speed of bus = s =45 mph

speed of car =s+15=45+15=60 mph