A car moves through 20 m in 3 minutes and the next 50 km at a speed of 100 km/h. What is the approximate average speed of the car?

A car moves through 20 m in 3 minutes.

1 minute = 60 seconds

3 minute = 180 seconds

Speed = $$\frac{distance}{time}$$

= $$\frac{20}{180}$$

= $$\frac{1}{9}$$ m/s

the next 50 km at a speed of 100 km/h.

distance = 50 km = 50000 m [1 km = 1000 m]

Speed = 100 km/h

= $$\frac{100\times1000}{3600}$$

= $$\frac{250}{9}$$ m/s

the approximate average speed of the car = $$\frac{20+50000}{\frac{20}{\frac{1}{9}}+\frac{50000}{\frac{250}{9}}}$$

= $$\frac{20+50000}{180+1800}$$

= $$\frac{50020}{1980}$$

= 25.26 m/s