Allison drove home at 60 mph, but her brother Austin, who left at the same time, could drive at only 44 mph. When Allison arrived, Austin still had 112 miles to go. How far did Allison drive?

420 miles.

Step-by-step explanation:

Let the distance Alison drove be x miles

For Allison: 60 = x/t ... (1)

For Austin: 44 = (x - 112) / t ... (2)

from (1):

t = x/60

from (2):

t = (x - 112) / 44

Equating the above 2 equations:

x / 60 = (x - 112) / 44

60x - 60*112 = 44x

16x = 60*112 = 6720

x = 6720 / 16

= 420 miles.