Really embarrassing math question

When I open a video file in VLC and press “+” it says: “Speed: 1.50x”. So if I have a 60 minute video and it plays 1.5 times the normal speed after how many minutes does it finish?
Do I calculate
a) 60 minutes / 1.5 = 45 minutes or
b) 60 minutes – (60 minutes / 100 * 50) = 30 minutes ?
Thanks.
Answer #1
I don’t know the algorithm that VLC uses, but for the equation, consider this.
If the speed was x 2.00, twice the speed, your 60 minute video would run in 30 minutes.
So…x1.5 speed would be….45 minutes.
Answer #2
Oh yes, didn’t think of that. 45 minutes sounds more logical now.