To take advantage of the offer, you'll need a coupon that is available only to e-club (email list) members. You can sign up at www.jackinthebox.com/offers.
A Jumbo Jack normally costs $2.59 in my area while a large drink is $2.89 (they have a $1 any-size drink special but it seems unlikely you can combine the two).
Photo via Jack in the Box.
