Bob drives from his house to his girlfriends house. When he gets there, he realizes he forgot the present he got her, so he drives back to his house, 20/km/hour faster, and takes 5 minutes less time. On the way back to her house again, he goes 20km/hour faster still, and it takes him 3 minutes less. How far does he live from her?
Does when he is returning to her house go 20km or does he now go 40km?
How can you figure this out without knowing how fast he went the first time?
PLEASE help!
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