Sunday brain teaser - how much did they cost?

OK - it took me a couple of minutes but I get

$1.20

$1.25

$1.50 

$3.16 

Juli - with or without tax?  Just joking ~ and delaying finding a solution. Brain too old.

Juli:  $1.7775   -  I know this is not really correct however it does work.  1.7775 x 4 - 7.11  

You're kidding, right?  I'm not even going to use the excuse it's too early - it's just too hard. 

FYI - 

You have 1 answer, two equasions (seemingly), but four possible varialbes.  At first glance, it seems impossible or too hard. 

I approached this by first converting the $7.11 to cents 711 - then I began to factor that number.  I won't go through that exercise, but ultimately that's what led to the solution.

Once I had the prime factors, some simple multiplication could be used to prove that no single number could be greater than 3.16.  I had my first answer.  

That left 3 variables and 3 equations, the first two, and a new third where the sum (only was less than 395).  Two fairly complex quadratic equations later I had an answer.  I had to use one quadratic as a variable in the other, and that is pretty confusing if you've never done it before.

Happy Sunday 

E

PS:  In a former life I was a biochemist.

I will have to watch for the correct answer.

Have an outstanding week, with your camera in hand.

Juli, Looks like Eric beat me to the punch, just didn't get here early enough to even try to figure it out :)

Juli - I *know* you aren't putting out tough math problems this early on a Sunday.....right...?  ;)

I have no trouble believing Eric was a biochemist in his past life - heh!

You think you have been going easy on us.  That's like Henry the 8th saying he was easy on his wives heads.

Good evening Juli.

I see that Eric got the correct answer.

Too late for me...