If + , - , * , / are the notation for subtraction,multiplication,division and addition respectively. Then 17 + 15 - 14 * 12 / 6 = ?

17-15*14/12+6 = 5.5

According to given condition 17 - 15 * 14 / 12 + 6 17 - (15*14)/12 + 6 = 17 - 17.5 + 6 = 5.5

If a/b = 21/34; b/c = 121/120; c/d = 17/77; e/f = 11/15 and d/e = 14/17 then what is the value of (abc/def)*2?