Aaron and Vanessa were relay race partners on a running team. Aaron was able to run each mile twice as fast as Vanessa, but Vanessa was able to run twice as far as Aaron did. If Vanessa ran 4 miles and Aaron completed his part of the race in 16 minutes, how long in minutes did Vanessa take to complete her part?
Vanessa ran twice as far as Aaron, so Aaron ran 4 / 2 = <<4/2=2>>2 miles.
Aaron took 16 minutes, so he ran each mile in 16 / 2 = <<16/2=8>>8 minutes.
Vanessa takes twice as long to run a mile, so she took 8 * 2 = <<8*2=16>>16 minutes for each mile.
She ran 4 miles, so she took 4 * 16 = <<4*16=64>>64 minutes to complete her part of the race.
#### 64