Neutrogena Coupon + a question...

[couponcool]

I have a duane reade circular coupon for $1 off and two printed $5 off coupons (from this website -- find it in the database). All coupons say "Limit one coupon per customer and one coupon per purchase." They are all manufacturer's coupons.

Does this mean I can only use one $5 or one $1 coupon? Or can I use both the $1 and $5 coupon? Heck, can I use all of them, and get $5 + $5 + $1 off?

Thanks for your help! I want to get the acne system which is $24.99, so $11 would be nice.