Machine P and Machine Q are each used to manufacture 990 sprockets. It takes Machine P 10 hours longer to produce 990 sprockets than Machine Q. Machine Q produces 10% more sprockets per hour than Machine A. How many sprockets per hour does Machine A produce?  Choose the most appropriate option
A) 5	B) 6	C) 7	D) 8	E) 9

Rationale: "p makes x sprockets per hour . then q makes 1.1 x sprockets per hour . 990 / x = 990 / 1.1 x + 10 1.1 ( 990 ) = 990 + 11 x 11 x = 99 x = 9 the answer is e ."
Answer: E