Salad dressing P is made up of 30% vinegar and 70% oil, and salad dressing Q contains 10% vinegar and 90% oil. If the two dressings are combined to produce a salad dressing that is 12% vinegar, dressing P comprises what percentage of the new dressing? Choose one:	A) 50 %	B) 40 %	C) 30 %	D) 20 %	E) 10 %

Rationale: let x be the percentage of dressing p in the new dressing . 0.3 x + 0.1 ( 1 - x ) = 0.12 0.2 x = 0.02 x = 0.1 = 10 % the answer is e .
Answer: E