Math
posted by Charu on .
Arman walks to the train station at 5 Km/h. He misses his train by 1 min. If he had run at 10 Km/h, he would have had 2 min to spare. How far is it to the station?

time = distance/speed
he took 3 minutes (3/60 hr) longer to walk than to run, so
d/5 = 3/60 + d/10
d/10 = 3/60
d = 1/2
check:
it takes 6 min to run 1/2 km at 5km/hr
it takes 3 min to run 1/2 km at 10km/hr