Question

The Bionic Woman gives Batman a 12 second

start in a 2 kilometre race. If the Bionic Woman
runs at 5 km/min, and Batman runs at 3 km/
min, who will win the race and by how many
seconds?​

Answer 1

The Bionic Woman will win the race by 4 s

Explanation:

`v=\frac st\quad\implies\quad t=\frac sv`

s = 2 km

t - time of run

v - speed of running

Batman:

v = 3km/min

`t = (2\,min)/(3\,(km)/(min))=2\,km\cdot(min)/(3\,km)=\frac23\,min = \frac23\cdot 60\,s=40\, s`

The Bionic Woman:

v = 5 km/min

`t = (2\,min)/(5\,(km)/(min))=2\,km\cdot(min)/(5\,km)=\frac25\,min = \frac25\cdot 60\,s=24\, s`

time from Batman's start: 24 s + 12 s = 36 s

40 - 36 = 4