A car travels 40 km/hr in kilometer and 60km/hr in another 1kilometer then find the average speed in 2 km

Question

A car travels 40km/hr in kilometer and 60km/hr in another 1km th then find the average speed? 

Answer 1

d=rt

1=40t

1/40 hr=t

d=rt

1=60t

1/60 hr=t

total distance=rate*total time

total time=(1/40)+(1/60)=(3/120)+(2/120)=5/120=1/24 hr

total distance=2 km

2=rate*(1/24)

(24)(2)=rate*(24)(1/24)

48=rate

rate=48 km per hr

you can also use the harmonic mean (look it up)

(2*40*60)/(40+60)

4800/100=48 again