If
three botles is equals to 30.. then 30/3 = 10...
therefore each bottles= 10

if 1 bottle which is 10 plus 2 burgers =20...10+5+5=20
means 1 burger =5.

if 1 burger which is 5 + 2 cups of beer = 5+2+2= 9
then a cup of beer =2..
therere
1 burger + 1 cup of beer + 1 bottle of soft drink=
5+2+10= 17
total= 17
follow, upvote my new post and comment there if correct... if wrong smile
;)