an airplane /car speed ratio

Question

An airplane traveled 2000 km in the same time that a car traveled 300 km. If the rate of the plane is 340 km/h greater than the rate of the car, find the rate of the car

Answer 1

d=rt

300=rt where r=rate of the car

2000=(r+340)t where (r+340)=rate of the plane

300/r=t

2000/(r+340)=t

2000/(r+340)=300/r because both are equal to t

cross multiply

2000*r=300*(r+340)

2000r=300r+102,000

2000r-300r=102,000

1700r=102,000

r=102,000/1700

r=60 km/hr is the rate of the car