#### Answer

$4$ miles

#### Work Step by Step

Charlene started to ride a bike to her friend's home.
After $3$ miles of bike riding, her bike got a flat tire.
She walked the $2$ remaining miles.
On her way back home, she walked the whole way:
$2+3=5$ miles.
She walked a total of:
$5+2=7$ miles.
This means that she walked:
$7-3=4$ more miles than she rode her bike.