A girl ran to a store at the rate of 6 miles per hour, and she walked back at the rate of 4 miles per hour. if it took 15 minutes for the round trip, how far away is the store?
distance=speed*time
d=6t
d=4(0.25-t) (15 minutes=15/60hours = 0.25 hours)
6t=4(0.25-t)
6t=1-4t
6t+4t=1
10t=1
t=1/10 of an hour
d=6t
d=6(1/10)
d=6/10 or 3/5 of a mile
the store is 6/10 or 3/5 of a mile away
