"How much voltage is dropped over a 150milliFarad cap after 3.33 seconds if it's charged by a 50v source through a 22K resistor?"

It's actually answered over here already.

https://answers.yahoo.com/question/index?qid=20130625103720AALu4qM

The textbook says Vc=Vie^(-t/RC)

I don't get why the Yahoo answer has a 1-e in it. What is the 1 doing there? If I copy Yahoo's work, it comes out ok, but if I go with the textbook I get 18v or something wrong.

Thanks for any help on this.