At a self-service station, 30% of the customers pump regular gas; 30% pump
midgrade gas, and 40% pump premium gas. Of those who pump regular gas,
21% pay at least $30, Of those who pump midgrade gas 49% pays at least $30 . And
of those who pump premium, 69% pay at least $30. What is the probability that
next customer pays at least $30?

ModEDIT: Try not to give direct answers hkstroud. This is obviously homework and there are specific rules concerning them.

I know it was a direct answer. I know it was homework. Having the answer won't do OP any good Op still has to show his/her work on paper.

To the Moderator
Please don't change my responses, I may not post on this board often but I'm no newbie around here.

Show us your attempt Marcov.